diff --git a/app/controllers/tags_controller.rb b/app/controllers/tags_controller.rb
index 6b03cff1e..c08f8a3e6 100644
--- a/app/controllers/tags_controller.rb
+++ b/app/controllers/tags_controller.rb
@@ -244,13 +244,16 @@ class TagsController < ApplicationController
     @taggings = ActsAsTaggableOn::Tagging.find_by_tag_id_and_taggable_id_and_taggable_type(@tag_id,@taggable_id,@taggable_type) unless @taggable_id.blank?
     @obj = get_object(@taggable_id,params[:taggableType]) unless @taggable_id.blank?
     if  @taggable_id.blank? #如果没有传tag_id，那么直接更新tag_name就好了。但是要防止 重命名后的tag存在。
-      #看重命名后的tag是否存在。如果存在的话，只需要更改taggings里边的id,
-      if @rename_tag
-        @taggings = ActsAsTaggableOn::Tagging.where(" `taggings`.`tag_id` = #{ @tag_id} AND `taggings`.`taggable_type` = 'Attachment' ")#find_by_tag_id_and_taggable_type(@tag_id,@taggable_type)
-        @taggings.each { |t| t.update_attributes({:tag_id=> @rename_tag.id}) if t.tag_id != @rename_tag.id }
-        ActsAsTaggableOn::Tag.find(@tag_id).update_attributes(:name=>@rename_tag_name)#并且将该tag改名
-      else #如果不存在，那么就直接更新该tag名称为新的名称
-        (ActsAsTaggableOn::Tag.find_by_name(@tag_name)).update_attributes(:name=>@rename_tag_name)
+      if @course_id
+        course = Course.find @course_id
+        course.attachments.each do |attachment|
+          taggings = ActsAsTaggableOn::Tagging.find_by_tag_id_and_taggable_id_and_taggable_type(@tag_id,attachment.id,attachment.class)
+          if taggings
+            taggings.delete
+            attachment.tag_list.add(@rename_tag_name.split(","))
+            attachment.save
+          end
+        end
       end
     else
       if(@rename_tag.nil?) #这次命名的是新的tag