diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index d266f5990..b89c407a3 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -217,6 +217,10 @@ class CoursesController < ApplicationController
       group.course_id = @course.id
       group.save
     end
+    @canShowCode = isCourseTeacher(User.current.id,@course) && params[:role] != '1'
+    @is_remote = true
+    @members = searchStudent(@course)
+    @membercount = @members.count
     @course_groups = @course.course_groups
   end
 
@@ -229,6 +233,8 @@ class CoursesController < ApplicationController
     @canShowCode = isCourseTeacher(User.current.id,@course) && params[:role] != '1'
     @is_remote = true
     @course_groups = @course.course_groups
+    @members = searchStudent(@course)
+    @membercount = @members.count
   end
   def join_group
     group = CourseGroup.find(params[:object_id])
@@ -283,11 +289,8 @@ class CoursesController < ApplicationController
         @members = searchTeacherAndAssistant(@course)
       when '2'
         @subPage_title = l :label_student_list
-        if @course_group_id
-           @members = search_student_in_group(@course, @course_group_id)
-        else
-          @members = searchStudent(@course)
-        end
+        @members = searchStudent(@course)
+        @membercount = @members.count
       else
         @subPage_title = ''
         @members = @course.member_principals.includes(:roles, :principal).all.sort
diff --git a/app/models/course_group.rb b/app/models/course_group.rb
index 6126352f6..c5c2f5c85 100644
--- a/app/models/course_group.rb
+++ b/app/models/course_group.rb
@@ -12,7 +12,7 @@ class CourseGroup < ActiveRecord::Base
   before_destroy :set_member_nil
 
   attr_accessible :name
-
+  validates :name, :presence => true, :length => {:maximum => 20}, :uniqueness => true
   def set_member_nil
     if self.members && self.members.count > 0
        self.members.update_all("course_group_id = 0")
diff --git a/app/views/courses/_groups_name.html.erb b/app/views/courses/_groups_name.html.erb
index 151eb9c7e..479bf27a5 100644
--- a/app/views/courses/_groups_name.html.erb
+++ b/app/views/courses/_groups_name.html.erb
@@ -1,4 +1,28 @@
+<script type=" text/javascript" charset="utf-8">
+    function validate_groupname(value1) {
 
+        if(value1.length > 20) {
+            alert('<%= l(:label_limit_groupname) %>');
+        }
+    }
+    function validate_groupname_null(value1) {
+
+        if(value1.length == 0) {
+            alert('<%= l(:label_limit_groupname_null) %>');
+        }
+    }
+    function validate_update(name) {
+         value1 = document.getElementsByName(name)[0].value;
+        validate_groupname(value1);
+        document.getElementsByName(name)[0].value = "";
+    }
+        function validate_add_group() {
+             value1 = document.getElementsByName("group_name")[0].value;
+            validate_groupname(value1);
+            validate_groupname_null(value1);
+            document.getElementsByName('group_name')[0].value = "";
+        }
+</script>"
 
 
     <ul>
@@ -6,7 +30,7 @@
       <li style=" color:#8b8b8b;">分班:</li>
 
       <li class="classbox">
-        <% course_member_count = l(:label_all) + "(" + @course.members.count.to_s + "人)" %>
+        <% course_member_count = l(:label_all) + "(" + @membercount.to_s + "人)" %>
       <%= form_tag( searchgroupmembers_course_path(@course, :group_id => 0), method: 'get',:remote=>true) do %>
 
 
@@ -30,9 +54,9 @@
       <li>
         <%= form_tag(updategroupname_course_path(@course,:group_id => group.id), method: 'get', remote:true, update: 'group_name') do %>
                 <span id="add_tag_<%= group.id %>" style="display:none; vertical-align: middle;" class=" f_l">
-                    <%= text_field_tag "group_name", params[:group_name], :size=>10, :class=>"isTxt w90 f_l", :style=>"padding: 0px", :max => 100 %>
+                    <%= text_field_tag "group_name", params[:group_name],:name => "group_name#{group.id}", :size=>10, :class=>"isTxt w90 f_l", :style=>"padding: 0px", :max => 20 %>
                     <!--<input type="button" class="submit f_l" onclick="addTag();" style="width: 43px"/>-->
-                  <%= submit_tag '', class: "submit f_l", style: "width: 43px;height: 21px;background: url(/images/btn.png) no-repeat 0 0;" %>
+                  <%= submit_tag '', class: "submit f_l", :onclick => "validate_update('group_name#{group.id}')", style: "width: 43px;height: 21px;background: url(/images/btn.png) no-repeat 0 0;" %>
                    </span>
             <% end %>
       </li>
@@ -47,7 +71,7 @@
         <%= form_tag( addgroups_course_path(@course),  method: 'get',:remote=>true) do %>
 
                     <%= text_field_tag "group_name", params[:group_name], size: "20", class: "isTxt w90 f_l", style: "padding: 0px",  maxlength: "100" %>
-                    <%= submit_tag '', class: "submit f_l", style: "width: 43px;height: 21px;background: url(/images/btn.png) no-repeat 0 0;" %>
+                    <%= submit_tag '', class: "submit f_l",:onclick => "validate_add_group()", style: "width: 43px;height: 21px;background: url(/images/btn.png) no-repeat 0 0;" %>
                     <%= link_to_function '', "$('#add_tag04').slideToggle();", class: "submit_2", style: "width: 43px"%>
 
        <% end %>
diff --git a/app/views/courses/_member_list.html.erb b/app/views/courses/_member_list.html.erb
index 436a339dd..2363d0fe5 100644
--- a/app/views/courses/_member_list.html.erb
+++ b/app/views/courses/_member_list.html.erb
@@ -1,5 +1,5 @@
 <div >
-<% if @group %>
+<% if User.current.logged? && User.current.member_of_course?(@course) && @group  %>
       <% if !@canShowCode %>
           <%= join_in_course_group(@course.course_groups,@group, User.current) %>
       <% end %>&nbsp;&nbsp;&nbsp;
diff --git a/config/locales/zh.yml b/config/locales/zh.yml
index cecc9b465..ce3181864 100644
--- a/config/locales/zh.yml
+++ b/config/locales/zh.yml
@@ -572,6 +572,8 @@ zh:
   label_member:
   label_search_member_count: 共搜索到
   label_member_people: 人
+  label_limit_groupname: 组别名不能超出20字符
+  label_limit_groupname_null: 组别名不能为空
   label_member_new: 添加成员
   label_member_plural: 成员
   label_tracker: 跟踪标签