diff --git a/src/main/java/run/halo/app/model/entity/BaseComment.java b/src/main/java/run/halo/app/model/entity/BaseComment.java
index 4f876a94d..df25c6f7c 100644
--- a/src/main/java/run/halo/app/model/entity/BaseComment.java
+++ b/src/main/java/run/halo/app/model/entity/BaseComment.java
@@ -132,7 +132,6 @@ public class BaseComment extends BaseEntity {
         if (isAdmin == null) {
             isAdmin = false;
         }
-
     }
 
 }
diff --git a/src/main/java/run/halo/app/model/entity/Journal.java b/src/main/java/run/halo/app/model/entity/Journal.java
index dbc27de4e..9f8ad7942 100644
--- a/src/main/java/run/halo/app/model/entity/Journal.java
+++ b/src/main/java/run/halo/app/model/entity/Journal.java
@@ -13,4 +13,13 @@ import javax.persistence.Entity;
 @DiscriminatorValue("2")
 public class Journal extends BaseComment {
 
+
+    @Override
+    public void prePersist() {
+        super.prePersist();
+
+        if (getPostId() == null) {
+            setPostId(0);
+        }
+    }
 }
diff --git a/src/main/java/run/halo/app/service/impl/BaseCommentServiceImpl.java b/src/main/java/run/halo/app/service/impl/BaseCommentServiceImpl.java
index e2f40c5d2..9109e56fc 100644
--- a/src/main/java/run/halo/app/service/impl/BaseCommentServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/BaseCommentServiceImpl.java
@@ -207,41 +207,40 @@ public abstract class BaseCommentServiceImpl<COMMENT extends BaseComment> extend
     }
 
     @Override
-    public COMMENT createBy(COMMENT COMMENT) {
-        Assert.notNull(COMMENT, "Domain must not be null");
+    public COMMENT createBy(COMMENT comment) {
+        Assert.notNull(comment, "Domain must not be null");
 
         // Check post id
-        boolean isPostExist = postRepository.existsById(COMMENT.getPostId());
-        if (!isPostExist) {
-            throw new NotFoundException("The post with id " + COMMENT.getPostId() + " was not found");
+        if (!ServiceUtils.isEmptyId(comment.getPostId())) {
+            postMustExist(comment.getPostId());
         }
 
         // Check parent id
-        if (!ServiceUtils.isEmptyId(COMMENT.getParentId())) {
-            mustExistById(COMMENT.getParentId());
+        if (!ServiceUtils.isEmptyId(comment.getParentId())) {
+            mustExistById(comment.getParentId());
         }
 
         // Check user login status and set this field
         Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
 
         // Set some default values
-        COMMENT.setIpAddress(ServletUtils.getRequestIp());
-        COMMENT.setUserAgent(ServletUtils.getHeaderIgnoreCase(HttpHeaders.USER_AGENT));
-        COMMENT.setGavatarMd5(DigestUtils.md5Hex(COMMENT.getEmail()));
+        comment.setIpAddress(ServletUtils.getRequestIp());
+        comment.setUserAgent(ServletUtils.getHeaderIgnoreCase(HttpHeaders.USER_AGENT));
+        comment.setGavatarMd5(DigestUtils.md5Hex(comment.getEmail()));
 
         if (authentication != null) {
             // Comment of blogger
-            COMMENT.setIsAdmin(true);
-            COMMENT.setStatus(CommentStatus.PUBLISHED);
+            comment.setIsAdmin(true);
+            comment.setStatus(CommentStatus.PUBLISHED);
         } else {
             // Comment of guest
             // Handle comment status
             Boolean needAudit = optionService.getByPropertyOrDefault(CommentProperties.NEW_NEED_CHECK, Boolean.class, true);
-            COMMENT.setStatus(needAudit ? CommentStatus.AUDITING : CommentStatus.PUBLISHED);
+            comment.setStatus(needAudit ? CommentStatus.AUDITING : CommentStatus.PUBLISHED);
         }
 
         // Create comment
-        COMMENT createdComment = create(COMMENT);
+        COMMENT createdComment = create(comment);
 
         if (ServiceUtils.isEmptyId(createdComment.getParentId())) {
             if (authentication == null) {
@@ -302,6 +301,18 @@ public abstract class BaseCommentServiceImpl<COMMENT extends BaseComment> extend
         return new BaseCommentDTO().convertFrom(comment);
     }
 
+    /**
+     * Post must exist.
+     *
+     * @param postId post id must not be null
+     */
+    protected void postMustExist(@NonNull Integer postId) {
+        boolean isPostExist = postRepository.existsById(postId);
+        if (!isPostExist) {
+            throw new NotFoundException("The post with id " + postId + " was not found");
+        }
+    }
+
     @NonNull
     protected Specification<COMMENT> buildSpecByQuery(@NonNull CommentQuery commentQuery) {
         Assert.notNull(commentQuery, "Comment query must not be null");
diff --git a/src/main/java/run/halo/app/service/impl/JournalServiceImpl.java b/src/main/java/run/halo/app/service/impl/JournalServiceImpl.java
index f4b564dc0..977415922 100644
--- a/src/main/java/run/halo/app/service/impl/JournalServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/JournalServiceImpl.java
@@ -6,6 +6,7 @@ import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
+import run.halo.app.exception.ForbiddenException;
 import run.halo.app.model.entity.Journal;
 import run.halo.app.model.entity.User;
 import run.halo.app.model.params.JournalParam;
@@ -16,6 +17,7 @@ import run.halo.app.security.authentication.Authentication;
 import run.halo.app.security.context.SecurityContextHolder;
 import run.halo.app.service.JournalService;
 import run.halo.app.service.OptionService;
+import run.halo.app.utils.ServiceUtils;
 import run.halo.app.utils.ValidationUtils;
 
 /**
@@ -51,6 +53,11 @@ public class JournalServiceImpl extends BaseCommentServiceImpl<Journal> implemen
             journalParam.setAuthor(StringUtils.isBlank(user.getNickname()) ? user.getUsername() : user.getNickname());
             journalParam.setAuthorUrl(optionService.getByPropertyOfNullable(BlogProperties.BLOG_URL));
             journalParam.setEmail(user.getEmail());
+        } else {
+            // Guest comment
+            if (ServiceUtils.isEmptyId(journalParam.getParentId())) {
+                throw new ForbiddenException("You have no right to create a journal");
+            }
         }
 
         // Validate the journal param