diff --git a/src/main/java/run/halo/app/controller/admin/api/PostController.java b/src/main/java/run/halo/app/controller/admin/api/PostController.java
index d69f1ff25..2db8c2f4b 100644
--- a/src/main/java/run/halo/app/controller/admin/api/PostController.java
+++ b/src/main/java/run/halo/app/controller/admin/api/PostController.java
@@ -38,7 +38,7 @@ public class PostController {
 
     @GetMapping
     @ApiOperation("Lists posts")
-    public Page<PostListVO> pageBy(@PageableDefault(sort = "updateTime", direction = DESC) Pageable pageable,
+    public Page<PostListVO> pageBy(@PageableDefault(sort = "createTime", direction = DESC) Pageable pageable,
                                    PostQuery postQuery) {
         Page<Post> postPage = postService.pageBy(postQuery, pageable);
         return postService.convertToListVo(postPage);
@@ -54,7 +54,7 @@ public class PostController {
     @ApiOperation("Gets a page of post by post status")
     public Page<? extends BasePostSimpleDTO> pageByStatus(@PathVariable(name = "status") PostStatus status,
                                                           @RequestParam(value = "more", required = false, defaultValue = "false") Boolean more,
-                                                          @PageableDefault(sort = "editTime", direction = DESC) Pageable pageable) {
+                                                          @PageableDefault(sort = "createTime", direction = DESC) Pageable pageable) {
         Page<Post> posts = postService.pageBy(status, pageable);
 
         if (more) {
diff --git a/src/main/java/run/halo/app/repository/CategoryRepository.java b/src/main/java/run/halo/app/repository/CategoryRepository.java
index 078e87a35..f01e079ee 100644
--- a/src/main/java/run/halo/app/repository/CategoryRepository.java
+++ b/src/main/java/run/halo/app/repository/CategoryRepository.java
@@ -4,6 +4,7 @@ import org.springframework.lang.NonNull;
 import run.halo.app.model.entity.Category;
 import run.halo.app.repository.base.BaseRepository;
 
+import java.util.List;
 import java.util.Optional;
 
 /**
@@ -44,4 +45,11 @@ public interface CategoryRepository extends BaseRepository<Category, Integer> {
      * @return Optional of Category
      */
     Optional<Category> getByName(@NonNull String name);
+
+    /**
+     * List categories by parent id.
+     * @param id parent id.
+     * @return list of category
+     */
+    List<Category> findByParentId(@NonNull Integer id);
 }
diff --git a/src/main/java/run/halo/app/service/CategoryService.java b/src/main/java/run/halo/app/service/CategoryService.java
index d0a76e021..fee7021cb 100755
--- a/src/main/java/run/halo/app/service/CategoryService.java
+++ b/src/main/java/run/halo/app/service/CategoryService.java
@@ -65,6 +65,12 @@ public interface CategoryService extends CrudService<Category, Integer> {
     @Transactional
     void removeCategoryAndPostCategoryBy(Integer categoryId);
 
+    /**
+     * List categories by parent id.
+     * @param id parent id.
+     * @return list of category.
+     */
+    List<Category> listByParentId(@NonNull Integer id);
 
     /**
      * Converts to category dto.
diff --git a/src/main/java/run/halo/app/service/impl/BasePostServiceImpl.java b/src/main/java/run/halo/app/service/impl/BasePostServiceImpl.java
index ee36ee138..30f2f1a3b 100644
--- a/src/main/java/run/halo/app/service/impl/BasePostServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/BasePostServiceImpl.java
@@ -137,7 +137,7 @@ public abstract class BasePostServiceImpl<POST extends BasePost> extends Abstrac
     public Page<POST> pageLatest(int top) {
         Assert.isTrue(top > 0, "Top number must not be less than 0");
 
-        PageRequest latestPageable = PageRequest.of(0, top, Sort.by(DESC, "editTime"));
+        PageRequest latestPageable = PageRequest.of(0, top, Sort.by(DESC, "createTime"));
 
         return listAll(latestPageable);
     }
@@ -152,7 +152,7 @@ public abstract class BasePostServiceImpl<POST extends BasePost> extends Abstrac
     public List<POST> listLatest(int top) {
         Assert.isTrue(top > 0, "Top number must not be less than 0");
 
-        PageRequest latestPageable = PageRequest.of(0, top, Sort.by(DESC, "editTime"));
+        PageRequest latestPageable = PageRequest.of(0, top, Sort.by(DESC, "createTime"));
         return basePostRepository.findAllByStatus(PostStatus.PUBLISHED, latestPageable).getContent();
     }
 
diff --git a/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java b/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java
index e7da2c132..c88323f0c 100644
--- a/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java
+++ b/src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java
@@ -165,12 +165,25 @@ public class CategoryServiceImpl extends AbstractCrudService<Category, Integer>
     @Override
     @Transactional
     public void removeCategoryAndPostCategoryBy(Integer categoryId) {
+        List<Category> categories = listByParentId(categoryId);
+        if (null != categories && categories.size() > 0) {
+            categories.forEach(category -> {
+                category.setParentId(0);
+                update(category);
+            });
+        }
         // Remove category
         removeById(categoryId);
         // Remove post categories
         postCategoryService.removeByCategoryId(categoryId);
     }
 
+    @Override
+    public List<Category> listByParentId(Integer id) {
+        Assert.notNull(id, "Parent id must not be null");
+        return categoryRepository.findByParentId(id);
+    }
+
     @Override
     public CategoryDTO convertTo(Category category) {
         Assert.notNull(category, "Category must not be null");