diff --git a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/controller/AssignmentController.java b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/controller/AssignmentController.java
index 2759f31..042c94d 100644
--- a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/controller/AssignmentController.java
+++ b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/controller/AssignmentController.java
@@ -2,6 +2,7 @@
 
 import backend.pirocheck.Assignment.dto.request.AssignmentCreateReq;
 import backend.pirocheck.Assignment.dto.request.AssignmentItemCreateReq;
+import backend.pirocheck.Assignment.dto.request.AssignmentItemUpdateReq;
 import backend.pirocheck.Assignment.dto.request.AssignmentUpdateReq;
 import backend.pirocheck.Assignment.dto.response.AssignmentWeekRes;
 import backend.pirocheck.Assignment.entity.AssignmentStatus;
@@ -119,13 +120,14 @@ public AssignmentStatus submissionAssignment(
             }
     )
     @PutMapping("/admin/users/{userId}/assignments/{assignmentId}/submission")
-    public String updateSubmission(
+    public AssignmentStatus updateSubmission(
             @Parameter(description = "사용자 ID", example = "1")
             @PathVariable Long userId,
             @Parameter(description = "과제 ID", example = "1")
-            @PathVariable Long assignmentId
+            @PathVariable Long assignmentId,
+            @RequestBody AssignmentItemUpdateReq req
     ) {
-        return null;
+        return assignmentService.updateAssignmentItem(userId, assignmentId, req);
     }
 
 }
diff --git a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/dto/request/AssignmentItemUpdateReq.java b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/dto/request/AssignmentItemUpdateReq.java
new file mode 100644
index 0000000..b917d54
--- /dev/null
+++ b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/dto/request/AssignmentItemUpdateReq.java
@@ -0,0 +1,16 @@
+package backend.pirocheck.Assignment.dto.request;
+
+import backend.pirocheck.Assignment.entity.AssignmentStatus;
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.Pattern;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class AssignmentItemUpdateReq {
+
+    @Pattern(regexp = "SUCCESS/INSUFFICIENT/FAILURE", message = "status는 SUCCESS, INSUFFICIENT 혹은 FAILURE 여야 합니다.")
+    @Schema(description = "과제 결과", example = "SUCCESS")
+    private AssignmentStatus status;
+}
diff --git a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/AssignmentItem.java b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/AssignmentItem.java
index 74719c7..6a9dddf 100644
--- a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/AssignmentItem.java
+++ b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/entity/AssignmentItem.java
@@ -35,4 +35,10 @@ public static AssignmentItem create(User user, Assignment assignment, Assignment
                 .submitted(submitted)
                 .build();
     }
+
+    public void update(AssignmentStatus submitted) {
+
+        this.submitted = submitted;
+
+    }
 }
diff --git a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/repository/AssignmentItemRepository.java b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/repository/AssignmentItemRepository.java
index 1a39eec..f07c351 100644
--- a/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/repository/AssignmentItemRepository.java
+++ b/backend/pirocheck/src/main/java/backend/pirocheck/Assignment/repository/AssignmentItemRepository.java
@@ -1,5 +1,6 @@
 package backend.pirocheck.Assignment.repository;
 
+import backend.pirocheck.Assignment.entity.Assignment;
 import backend.pirocheck.Assignment.entity.AssignmentItem;
 import backend.pirocheck.Assignment.entity.AssignmentStatus;
 import backend.pirocheck.User.entity.User;
@@ -7,6 +8,7 @@
 import org.springframework.stereotype.Repository;
 
 import java.util.List;
+import java.util.Optional;
 
 @Repository
 public interface AssignmentItemRepository extends JpaRepository<AssignmentItem, Long> {
@@ -17,4 +19,7 @@ public interface AssignmentItemRepository extends JpaRepository<AssignmentItem,
     // 보증금
     int countByUserAndSubmitted(User user, AssignmentStatus status);
 
+    Optional<AssignmentItem> findByUserAndAssignment(User user, Assignment assignment);
+    // Optional 처리로 오류 발생 check
+
 }
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 f1ef8ef..e589e2c 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
@@ -2,6 +2,7 @@
 
 import backend.pirocheck.Assignment.dto.request.AssignmentCreateReq;
 import backend.pirocheck.Assignment.dto.request.AssignmentItemCreateReq;
+import backend.pirocheck.Assignment.dto.request.AssignmentItemUpdateReq;
 import backend.pirocheck.Assignment.dto.request.AssignmentUpdateReq;
 import backend.pirocheck.Assignment.dto.response.AssignmentDayRes;
 import backend.pirocheck.Assignment.dto.response.AssignmentDetailRes;
@@ -14,6 +15,7 @@
 import backend.pirocheck.User.entity.User;
 import backend.pirocheck.User.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -22,6 +24,7 @@
 import java.util.Map;
 import java.util.stream.Collectors;
 
+@Slf4j // 로그를 찍기위해 사용
 @Service
 @Transactional
 @RequiredArgsConstructor
@@ -118,7 +121,9 @@ public String updateAssignment(Long assignmentId, AssignmentUpdateReq req) {
     }
 
     // 과제 채점 결과 저장
-    public AssignmentStatus createAssignmentItem(Long assignmentId, Long userId, AssignmentItemCreateReq req) {
+    public AssignmentStatus createAssignmentItem(Long userId, Long assignmentId, AssignmentItemCreateReq req) {
+        log.info("userId 요청 값: {}", userId);
+
         User user = userRepository.findById(userId)
                 .orElseThrow(() -> new IllegalArgumentException("조회된 사용자가 없습니다."));
 
@@ -135,4 +140,22 @@ public AssignmentStatus createAssignmentItem(Long assignmentId, Long userId, Ass
 
         return assignmentItem.getSubmitted();
     }
+
+    // 과제 채점 결과 수정
+    public AssignmentStatus updateAssignmentItem(Long userId, Long assignmentId, AssignmentItemUpdateReq req) {
+        User user = userRepository.findById(userId)
+                .orElseThrow(() -> new IllegalArgumentException("조회된 사용자가 없습니다."));
+
+        Assignment assignment = assignmentRepository.findById(assignmentId)
+                .orElseThrow(() -> new IllegalArgumentException("조회된 과제가 없습니다."));
+
+        AssignmentItem assignmentItem = assignmentItemRepository.findByUserAndAssignment(user, assignment)
+                .orElseThrow(() -> new IllegalArgumentException("해당 유저의 과제 채점 결과가 없습니다."));
+
+        assignmentItem.update(req.getStatus()); // 상태 업데이트
+
+        assignmentItemRepository.save(assignmentItem); // 상태 저장
+
+        return assignmentItem.getSubmitted();
+    }
 }