diff --git a/src/main/java/leets/weeth/domain/post/entity/Comment.java b/src/main/java/leets/weeth/domain/post/entity/Comment.java
index 1b08311..92ce443 100644
--- a/src/main/java/leets/weeth/domain/post/entity/Comment.java
+++ b/src/main/java/leets/weeth/domain/post/entity/Comment.java
@@ -41,17 +41,22 @@ public class Comment extends BaseEntity {
     @Column(nullable = false)
     private Boolean isDeleted;
 
-    @OneToMany(orphanRemoval = true)
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "parent_id")
+    private Comment parent;
+
+    @OneToMany(mappedBy = "parent", cascade = CascadeType.REMOVE, fetch = FetchType.LAZY)
     private List<Comment> children = new ArrayList<>();
 
     LocalDateTime time;
 
-    public static Comment createComment(RequestCommentDTO dto, Post post, User user){
+    public static Comment createComment(RequestCommentDTO dto, Post post, User user, Comment parent){
         return Comment.builder()
                 .post(post)
                 .user(user)
                 .content(dto.getContent())
                 .isDeleted(false)
+                .parent(parent)
                 .build();
     }
 
diff --git a/src/main/java/leets/weeth/domain/post/entity/Post.java b/src/main/java/leets/weeth/domain/post/entity/Post.java
index 82d4639..bf778b2 100644
--- a/src/main/java/leets/weeth/domain/post/entity/Post.java
+++ b/src/main/java/leets/weeth/domain/post/entity/Post.java
@@ -37,7 +37,7 @@ public class Post extends BaseEntity {
     @Column(columnDefinition = "TEXT")
     private String content;
 
-    @OneToMany(orphanRemoval = true)
+    @OneToMany(mappedBy = "post", orphanRemoval = true)
     @JsonManagedReference
     private List<Comment> parentComments = new ArrayList<>();
 
diff --git a/src/main/java/leets/weeth/domain/post/service/CommentService.java b/src/main/java/leets/weeth/domain/post/service/CommentService.java
index e233ea3..9bddfe1 100644
--- a/src/main/java/leets/weeth/domain/post/service/CommentService.java
+++ b/src/main/java/leets/weeth/domain/post/service/CommentService.java
@@ -8,9 +8,13 @@
 import leets.weeth.domain.post.repository.PostRepository;
 import leets.weeth.domain.user.entity.User;
 import leets.weeth.domain.user.repository.UserRepository;
-import leets.weeth.global.common.error.exception.custom.*;
+import leets.weeth.global.common.error.exception.custom.CommentNotFoundException;
+import leets.weeth.global.common.error.exception.custom.PostNotFoundException;
+import leets.weeth.global.common.error.exception.custom.UserMismatchException;
+import leets.weeth.global.common.error.exception.custom.UserNotFoundException;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
+
 import java.util.List;
 
 @RequiredArgsConstructor
@@ -20,30 +24,25 @@ public class CommentService {
     private final UserRepository userRepository;
     private final CommentRepository commentRepository;
 
+    @Transactional
     public void createComment(Long userId, Long postId, RequestCommentDTO requestCommentDTO) {
         User user = userRepository.findById(userId)
                 .orElseThrow(UserNotFoundException::new);
-        // 해당 유저가 없는 경우
-        Post currentPost = postRepository.findById(postId).orElseThrow(PostNotFoundException::new);
-        // 해당 게시물이 없는 경우
-        
-        Comment newComment = Comment.createComment(requestCommentDTO, currentPost, user);
-        Comment parentComment;
-        commentRepository.save(newComment);
-        // 댓글이 child인 경우(부모가 있는 경우)
-        if(requestCommentDTO.getParentCommentId()!=null){
-            parentComment = commentRepository.findById(requestCommentDTO.getParentCommentId())
-                    .orElseThrow(CommentNotFoundException::new);
-            parentComment.addChild(newComment);
-            // 자식 추가
-            commentRepository.save(parentComment);
-        }
-        else{
-            // 댓글이 부모인 경우
-            currentPost.addComment(newComment);
-            postRepository.save(currentPost);
-        }
-        postRepository.save(currentPost);
+
+        Post post = postRepository.findById(postId).orElseThrow(PostNotFoundException::new);
+
+        Comment parent = null;
+        if(requestCommentDTO.getParentCommentId() != null)
+            parent = commentRepository.findById(requestCommentDTO.getParentCommentId())
+                .orElseThrow(CommentNotFoundException::new);
+
+        Comment comment = Comment.createComment(requestCommentDTO, post, user, parent);
+        commentRepository.save(comment);
+
+        if(parent == null)
+            post.addComment(comment);
+        else
+            parent.addChild(comment);
     }
 
     @Transactional