diff --git a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/Assignment.java b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/Assignment.java
index 410c522..eede8f9 100644
--- a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/Assignment.java
+++ b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/Assignment.java
@@ -37,6 +37,7 @@ public class Assignment {
     // AssignmentItem 입장에서 "assignment" 필드의 외래 키를 가진 주인
     // assignment를 참조하는 assignmentitem 컬랙션을 가짐
     @OneToMany(mappedBy = "assignment", cascade = CascadeType.ALL, orphanRemoval = true)
+    @Builder.Default
     private List<AssignmentItem> assignments = new ArrayList<>();
 
     // 연관관계 편의 메서드 (양방향 시 자주 사용)
diff --git a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/service/AssignmentService.java b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/service/AssignmentService.java
index c4c25cd..f1ef8ef 100644
--- a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/service/AssignmentService.java
+++ b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/service/AssignmentService.java
@@ -83,6 +83,20 @@ public String createAssignment(AssignmentCreateReq assignmentCreateReq) {
 
         assignment = assignmentRepository.save(assignment);
 
+        // 전체 유저에게 과제 자동 할당
+        List<User> users = userRepository.findAll();
+
+        for (User user : users) {
+
+            AssignmentItem item = AssignmentItem.create(user, assignment, AssignmentStatus.INSUFFICIENT);
+
+            assignment.addAssignmentItem(item);
+            user.addAssignmentItem(item);
+
+//            assignmentItemRepository.save(item);
+// Cascade 설정이 되어있으므로 assignment = assignmentRepository.save(assignment); 이 코드를 실행할 때 연관된 AssignmentItem도 함께 저장 됨
+        }
+
         return assignment.getAssignmentName();
     }