diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index edd3f1b9d..dcd09959d 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -273,6 +273,7 @@ class CoursesController < ApplicationController
 
     if valid_attr.eql?('name')
       faker.name = valid_value
+     # faker.course_id = @course.id
       faker.valid?
       req[:valid] = faker.errors[:name].blank?
       req[:message] = faker.errors[:name]
diff --git a/app/models/course_group.rb b/app/models/course_group.rb
index 144c43c6e..c1236da93 100644
--- a/app/models/course_group.rb
+++ b/app/models/course_group.rb
@@ -12,11 +12,20 @@ class CourseGroup < ActiveRecord::Base
   before_destroy :set_member_nil
 
   attr_accessible :name
-  validates :name, :presence => true, :length => {:maximum => 20},
-            :uniqueness => {case_sensitive: false}
+  validates :name, :presence => true, :length => {:maximum => 20}
+ validate_on_create :unique_name_and_course
+
+
+
   def set_member_nil
     if self.members && self.members.count > 0
        self.members.update_all("course_group_id = 0")
     end
   end
+  private
+  def unique_name_and_course
+    if CourseGroup.find(:conditions => ["name=? and course_id=?", name, course_id]).first
+      errors.add_to_base("该班名已被使用!")
+    end
+  end
 end