We are now in the information age in which our society is becoming more and more knowledge –depend—knowledge plus information equals power plus power equals influence. So it is imperative that we understand (among other things) how collective intelligence processes can be encouraged and expanded in classrooms through the use of Web 2.0 tools such as the wiki. Harnessing a group's collective intelligence is one of the keys to success for modern societies. While in the writing class teaching, writing is an individual work at the most of time. Students not only need to know how to write, but they also need to know how to improve their own work. Therefore, teachers of writing class should find ways of using some tools to meet students’ such kind of needs.Wiki has many features,it could be an effective tool to help teachers achieve that educational aim. Teaching with wikis is a way of adding a new dimension and atmosphere to the classroom.