diff --git a/app/views/boards/_course_show_detail.html.erb b/app/views/boards/_course_show_detail.html.erb
index 75ee516c4..f971776f1 100644
--- a/app/views/boards/_course_show_detail.html.erb
+++ b/app/views/boards/_course_show_detail.html.erb
@@ -42,15 +42,21 @@
             $(function () {
                 init_activity_KindEditor_data(<%= topic.id%>, null, "87%");
                 showNormalImage('activity_description_<%= topic.id %>');
-                /*var description_images=$("div#activity_description_<%#= topic.id %>").find("img");
-                 if (description_images.length>0) {
-                 for (var i=0; i<description_images.length; i++){
-                 var image=$(description_images[i]);
-                 var element=$("<a></a>").attr("href",image.attr('src'));
-                 image.wrap(element);
-                 }
-                 }
-                 $('#activity_description_<%#= topic.id %> a').colorbox({rel:'nofollow', close: "关闭", returnFocus: false});*/
+                if($("#intro_content_<%= topic.id %>").height() > 360) {
+                    $("#intro_content_show_<%= topic.id %>").show();
+                }
+                $("#intro_content_show_<%= topic.id %>").click(function(){
+                    $("#activity_description_<%= topic.id %>").toggleClass("maxh360");
+                    $("#activity_description_<%= topic.id%>").toggleClass("lh18");
+                    $("#intro_content_show_<%= topic.id %>").hide();
+                    $("#intro_content_hide_<%= topic.id %>").show();
+                });
+                $("#intro_content_hide_<%= topic.id %>").click(function(){
+                    $("#activity_description_<%= topic.id %>").toggleClass("maxh360");
+                    $("#activity_description_<%= topic.id%>").toggleClass("lh18");
+                    $("#intro_content_hide_<%= topic.id %>").hide();
+                    $("#intro_content_show_<%= topic.id %>").show();
+                });
             });
         </script>
         <% if topic %>
diff --git a/public/stylesheets/public.css b/public/stylesheets/public.css
index 7f9a4ad7a..e36f477d5 100644
--- a/public/stylesheets/public.css
+++ b/public/stylesheets/public.css
@@ -959,5 +959,5 @@ span.at {color:#269ac9;}
 .orgSendSearch {border:1px solid #dddddd; outline:none; width:262px; height:22px; padding-left:10px; float:left;}
 
 /*文本描述展开高度*/
-.maxh360 {max-height: 760px;}
+.maxh360 {max-height: 810px;}
 .lh18 { line-height: 18px;}
\ No newline at end of file