diff --git a/src/django-master/comments/models.py b/src/django-master/comments/models.py
index 7c3bbc8..b228a4e 100644
--- a/src/django-master/comments/models.py
+++ b/src/django-master/comments/models.py
@@ -4,14 +4,14 @@ from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 
 from blog.models import Article
-
+from django.utils import timezone
 
 # Create your models here.
 
 class Comment(models.Model):
     body = models.TextField('正文', max_length=300)
     creation_time = models.DateTimeField(_('creation time'), default=now)
-    last_modify_time = models.DateTimeField(_('last modify time'), default=now)
+   last_modify_time = models.DateTimeField(_('last modify time'), default=timezone.now)
     author = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         verbose_name=_('author'),
@@ -37,3 +37,9 @@ class Comment(models.Model):
 
     def __str__(self):
         return self.body
+
+    def save(self, *args, **kwargs):
+        if not self.id:  # 如果是新对象，creation_time 将由 default=timezone.now 处理
+            self.creation_time = timezone.now()
+        self.last_modify_time = timezone.now()
+        super(Comment, self).save(*args, **kwargs)