diff --git a/lib/features/trips/controller/trip_belonging_controller.dart b/lib/features/trips/controller/trip_belonging_controller.dart
index 6cbe7b51..a76b0e89 100644
--- a/lib/features/trips/controller/trip_belonging_controller.dart
+++ b/lib/features/trips/controller/trip_belonging_controller.dart
@@ -1,6 +1,9 @@
+import 'package:flutter/material.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
+import 'package:trip_app_nativeapp/core/exception/exception_handler.dart';
 import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/trip_belonging.dart';
 import 'package:trip_app_nativeapp/features/trips/domain/interactor/trip_interactor.dart';
+import 'package:trip_app_nativeapp/view/widgets/common/loading.dart';
 
 part 'trip_belonging_controller.g.dart';
 
@@ -8,8 +11,29 @@ part 'trip_belonging_controller.g.dart';
 class TripBelongingsController extends _$TripBelongingsController {
   @override
   FutureOr<List<AddedTripBelonging>> build({required int tripId}) async {
-    return ref
-        .read(tripInteractorProvider)
-        .fetchTripBelongings(tripId);
+    return ref.read(tripInteractorProvider).fetchTripBelongings(tripId);
+  }
+
+  Future<void> addBelonging({
+    required int tripId,
+    required String name,
+    required int numOf,
+    required bool isShareAmongMember,
+    VoidCallback? onFinished,
+  }) async {
+    try {
+      final result = await ref.read(tripInteractorProvider).addTripBelonging(
+            tripId: tripId,
+            name: name,
+            numOf: numOf,
+            isShareAmongMember: isShareAmongMember,
+          );
+      state = AsyncValue.data([result, ...state.value ?? []]);
+    } on Exception catch (e) {
+      ref.read(exceptionHandlerProvider).handleException(e);
+    } finally {
+      ref.read(overlayLoadingProvider.notifier).endLoading();
+      onFinished?.call();
+    }
   }
 }
diff --git a/lib/features/trips/domain/interactor/trip_interactor.dart b/lib/features/trips/domain/interactor/trip_interactor.dart
index 1a96251b..e3b40c69 100644
--- a/lib/features/trips/domain/interactor/trip_interactor.dart
+++ b/lib/features/trips/domain/interactor/trip_interactor.dart
@@ -3,6 +3,8 @@ import 'package:trip_app_nativeapp/features/trips/data/repositories/trip_reposit
 import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/trip.dart';
 import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/trip_belonging.dart';
 import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/trip_invitation.dart';
+import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/value/trip_belonging_name.dart';
+import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/value/trip_belonging_num.dart';
 import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/value/trip_invitation_num.dart';
 import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/value/trip_period.dart';
 import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/value/trip_title.dart';
@@ -56,6 +58,21 @@ class TripInteractor {
   Future<List<ExistingTrip>> fetchTripsByUserId(int userId) =>
       tripRepo.fetchTripsByUserId(userId);
 
+  Future<AddedTripBelonging> addTripBelonging({
+    required int tripId,
+    required String name,
+    required int numOf,
+    required bool isShareAmongMember,
+  }) {
+    final belonging = TripBelonging.createNewTripBelonging(
+     name: TripBelongingName(value: name),
+      numOf: TripBelongingNum(value: numOf),
+      isShareAmongMember: isShareAmongMember,
+    ) as NewTripBelonging;
+
+    return tripRepo.addTripBelonging(tripId, belonging);
+  }
+
   Future<List<AddedTripBelonging>> fetchTripBelongings(int tripId) =>
       tripRepo.fetchTripBelongings(tripId);
 }
diff --git a/lib/view/widgets/trips/add_trip_belonging_sheet.dart b/lib/view/widgets/trips/add_trip_belonging_sheet.dart
new file mode 100644
index 00000000..d9c302cc
--- /dev/null
+++ b/lib/view/widgets/trips/add_trip_belonging_sheet.dart
@@ -0,0 +1,208 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_hooks/flutter_hooks.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:trip_app_nativeapp/core/extensions/build_context.dart';
+import 'package:trip_app_nativeapp/features/trips/controller/trip_belonging_controller.dart';
+
+class AddTripBelongingSheet extends HookConsumerWidget {
+  const AddTripBelongingSheet(this.tripId, {super.key});
+
+  final int tripId;
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final titleEditingController = useTextEditingController();
+    final numOfEditingController = useTextEditingController();
+
+    final isTitleEmpty = useState<bool>(true);
+    final isNumOfEmpty = useState<bool>(true);
+    final isShareAmongMember = useState<bool>(false);
+
+    useEffect(
+      () {
+        titleEditingController.addListener(
+          () => isTitleEmpty.value = titleEditingController.text.isEmpty,
+        );
+        numOfEditingController.addListener(
+          () => isNumOfEmpty.value = numOfEditingController.text.isEmpty,
+        );
+        return null;
+      },
+      [titleEditingController, numOfEditingController],
+    );
+
+    return Container(
+      padding: EdgeInsets.only(
+        bottom: MediaQuery.of(context).viewInsets.bottom,
+      ),
+      height: 280,
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          _TitleTextField(
+            controller: titleEditingController,
+            isTitleEmpty: isTitleEmpty,
+          ),
+          _NumOfForm(
+            controller: numOfEditingController,
+            isNumEmpty: isNumOfEmpty,
+          ),
+          _IsShareCheckBoxRow(isShareAmongMember: isShareAmongMember),
+          _CreateButton(
+            tripId: tripId,
+            titleEditingController: titleEditingController,
+            numOfEditingController: numOfEditingController,
+            isTitleEmpty: isTitleEmpty,
+            isNumOfEmpty: isNumOfEmpty,
+            isShareAmongMember: isShareAmongMember,
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _TitleTextField extends StatelessWidget {
+  const _TitleTextField({
+    required this.controller,
+    required this.isTitleEmpty,
+  });
+
+  final TextEditingController controller;
+  final ValueNotifier<bool> isTitleEmpty;
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+      child: DecoratedBox(
+        decoration: BoxDecoration(
+          borderRadius: BorderRadius.circular(16),
+          border: Border.all(
+            color: isTitleEmpty.value
+                ? context.theme.colorScheme.secondaryContainer
+                : context.theme.colorScheme.primary,
+          ),
+        ),
+        child: TextField(
+          autofocus: true,
+          controller: controller,
+          decoration: const InputDecoration(
+            hintText: '持ち物名🧳',
+            border: InputBorder.none,
+            contentPadding: EdgeInsets.all(16),
+          ),
+          style: TextStyle(
+            color: context.theme.colorScheme.primary,
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _NumOfForm extends HookWidget {
+  const _NumOfForm({
+    required this.controller,
+    required this.isNumEmpty,
+  });
+
+  final TextEditingController controller;
+  final ValueNotifier<bool> isNumEmpty;
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+      child: DecoratedBox(
+        decoration: BoxDecoration(
+          borderRadius: BorderRadius.circular(16),
+          border: Border.all(
+            color: isNumEmpty.value
+                ? context.theme.colorScheme.secondaryContainer
+                : context.theme.colorScheme.primary,
+          ),
+        ),
+        child: TextField(
+          controller: controller,
+          keyboardType: TextInputType.number,
+          decoration: const InputDecoration(
+            hintText: '個数',
+            border: InputBorder.none,
+            contentPadding: EdgeInsets.all(16),
+          ),
+          style: TextStyle(
+            color: context.theme.colorScheme.primary,
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _IsShareCheckBoxRow extends HookWidget {
+  const _IsShareCheckBoxRow({
+    required this.isShareAmongMember,
+  });
+
+  final ValueNotifier<bool> isShareAmongMember;
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      children: [
+        Checkbox(
+          value: isShareAmongMember.value,
+          onChanged: (value) => isShareAmongMember.value = value ?? false,
+          fillColor: context.theme.checkboxTheme.checkColor,
+        ),
+        InkWell(
+          child: const Text('他のメンバーと共有する？'),
+          onTap: () => isShareAmongMember.value = !isShareAmongMember.value,
+        ),
+      ],
+    );
+  }
+}
+
+class _CreateButton extends ConsumerWidget {
+  const _CreateButton({
+    required this.tripId,
+    required this.titleEditingController,
+    required this.numOfEditingController,
+    required this.isTitleEmpty,
+    required this.isNumOfEmpty,
+    required this.isShareAmongMember,
+  });
+
+  final int tripId;
+  final TextEditingController titleEditingController;
+  final TextEditingController numOfEditingController;
+  final ValueNotifier<bool> isTitleEmpty;
+  final ValueNotifier<bool> isNumOfEmpty;
+  final ValueNotifier<bool> isShareAmongMember;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return SizedBox(
+      width: context.displaySize.width * 0.2,
+      child: ElevatedButton(
+        onPressed: isTitleEmpty.value || isNumOfEmpty.value
+            ? null
+            : () {
+                ref
+                    .read(
+                      tripBelongingsControllerProvider(tripId: tripId).notifier,
+                    )
+                    .addBelonging(
+                      tripId: tripId,
+                      name: titleEditingController.text,
+                      numOf: int.parse(numOfEditingController.text),
+                      isShareAmongMember: isShareAmongMember.value,
+                      onFinished: () => Navigator.pop(context),
+                    );
+              },
+        child: const Text('作成'),
+      ),
+    );
+  }
+}
diff --git a/lib/view/widgets/trips/trip_belonging_list.dart b/lib/view/widgets/trips/trip_belonging_list.dart
index 794a2f1a..fd834bfc 100644
--- a/lib/view/widgets/trips/trip_belonging_list.dart
+++ b/lib/view/widgets/trips/trip_belonging_list.dart
@@ -4,6 +4,7 @@ import 'package:trip_app_nativeapp/core/extensions/build_context.dart';
 import 'package:trip_app_nativeapp/features/trips/controller/trip_belonging_controller.dart';
 import 'package:trip_app_nativeapp/view/widgets/common/car_driving_loading.dart';
 import 'package:trip_app_nativeapp/view/widgets/common/error_cat.dart';
+import 'package:trip_app_nativeapp/view/widgets/trips/add_trip_belonging_sheet.dart';
 
 class TripBelongingList extends HookConsumerWidget {
   const TripBelongingList(this.tripId, {super.key});
@@ -11,9 +12,7 @@ class TripBelongingList extends HookConsumerWidget {
   final int tripId;
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    return ref
-        .watch(tripBelongingsControllerProvider(tripId: tripId))
-        .when(
+    return ref.watch(tripBelongingsControllerProvider(tripId: tripId)).when(
           data: (belongings) {
             return Column(
               children: [
@@ -41,6 +40,17 @@ class TripBelongingList extends HookConsumerWidget {
                     },
                   ),
                 ),
+                Padding(
+                  padding: const EdgeInsets.all(8),
+                  child: FloatingActionButton(
+                    onPressed: () => showModalBottomSheet<void>(
+                      context: context,
+                      isScrollControlled: true,
+                      builder: (context) => AddTripBelongingSheet(tripId),
+                    ),
+                    child: const Icon(Icons.add, color: Colors.white),
+                  ),
+                ),
               ],
             );
           },
diff --git a/test/feature/trips/controller/trip_belonging_controller_test.dart b/test/feature/trips/controller/trip_belonging_controller_test.dart
new file mode 100644
index 00000000..ef767de9
--- /dev/null
+++ b/test/feature/trips/controller/trip_belonging_controller_test.dart
@@ -0,0 +1,137 @@
+import 'package:dio/dio.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:http_mock_adapter/http_mock_adapter.dart';
+import 'package:mocktail/mocktail.dart';
+import 'package:trip_app_nativeapp/core/http/api_client/api_destination.dart';
+import 'package:trip_app_nativeapp/core/http/api_client/dio/dio.dart';
+import 'package:trip_app_nativeapp/features/trips/controller/trip_belonging_controller.dart';
+import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/trip_belonging.dart';
+import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/value/trip_belonging_name.dart';
+import 'package:trip_app_nativeapp/features/trips/domain/entity/trip/value/trip_belonging_num.dart';
+
+import '../../../mock/async_value_listener.dart';
+
+Future<void> main() async {
+  late ProviderContainer providerContainer;
+
+  final dio = Dio(BaseOptions(validateStatus: (status) => true));
+  final dioAdapter = DioAdapter(dio: dio);
+
+  const testTripId = 1;
+  final testFetchBelongings = [
+    AddedTripBelonging(
+      id: 1,
+      name: TripBelongingName(value: '持ち物1'),
+      numOf: TripBelongingNum(value: 5),
+      isShareAmongMember: true,
+      isChecked: false,
+    ),
+    AddedTripBelonging(
+      id: 2,
+      name: TripBelongingName(value: '持ち物2'),
+      numOf: TripBelongingNum(value: 10),
+      isShareAmongMember: true,
+      isChecked: true,
+    ),
+  ];
+
+  final testAddBelonging = AddedTripBelonging(
+    id: 3,
+    name: TripBelongingName(value: '持ち物3'),
+    numOf: TripBelongingNum(value: 10),
+    isShareAmongMember: false,
+    isChecked: false,
+  );
+
+  final asyncValueListener =
+      AsyncValueListener<AsyncValue<List<AddedTripBelonging>>>();
+
+  setUp(() {
+    dioAdapter.onGet(
+      '/trips/$testTripId/belongings',
+      (server) => server.reply(
+        200,
+        <String, dynamic>{
+          'data': [
+            {
+              'id': 1,
+              'name': '持ち物1',
+              'num_of': 5,
+              'is_share_among_member': true,
+              'is_checked': false,
+            },
+            {
+              'id': 2,
+              'name': '持ち物2',
+              'num_of': 10,
+              'is_share_among_member': true,
+              'is_checked': true,
+            }
+          ],
+        },
+      ),
+    );
+    providerContainer = ProviderContainer(
+      overrides: [
+        dioProvider(ApiDestination.privateTripAppV1).overrideWithValue(dio),
+      ],
+    )..listen(
+        tripBelongingsControllerProvider(tripId: testTripId),
+        asyncValueListener.call,
+        fireImmediately: true,
+      );
+  });
+
+  group('コンストラクター', () {
+    test('正常系', () async {
+      final result = await providerContainer
+          .read(tripBelongingsControllerProvider(tripId: testTripId).future);
+
+      expect(result, testFetchBelongings);
+      verify(
+        () => asyncValueListener(
+          null,
+          const AsyncLoading<List<AddedTripBelonging>>(),
+        ),
+      );
+    });
+  });
+
+  group('addBelonging', () {
+    test('正常系', () async {
+      dioAdapter.onPost(
+        '/trips/$testTripId/belongings',
+        data: {
+          'name': testAddBelonging.name.value,
+          'num_of': testAddBelonging.numOf.value,
+          'is_share_among_member': testAddBelonging.isShareAmongMember,
+        },
+        (server) => server.reply(
+          201,
+          <String, dynamic>{
+            'data': {
+              'id': 3,
+              'name': testAddBelonging.name.value,
+              'num_of': testAddBelonging.numOf.value,
+              'is_share_among_member': testAddBelonging.isShareAmongMember,
+              'is_checked': false,
+            },
+          },
+        ),
+      );
+      await providerContainer
+          .read(tripBelongingsControllerProvider(tripId: testTripId).notifier)
+          .addBelonging(
+            tripId: testTripId,
+            name: testAddBelonging.name.value,
+            numOf: testAddBelonging.numOf.value,
+            isShareAmongMember: testAddBelonging.isShareAmongMember,
+          );
+      final result = await providerContainer.read(
+        tripBelongingsControllerProvider(tripId: testTripId).future,
+      );
+      expect(result, [testAddBelonging, ...testFetchBelongings]);
+    });
+  });
+}