Abstract: In order to write effectively, students need to establish the central idea in the pre-writing stage, select proper words and structures to express their meaning in writing and evaluate their essay after writing. During this process, various critical skills are required. These critical skills can be acquired and enhanced if students are exposed to Critical Discourse Studies in their classroom. This paper first analyzes the research methodologies of the mainstream approaches to critical discourse analysis to make a comprehensive overview of how critical analysts carry out discourse studies. Then views from Critical Discourse analysis are discussed on account of their value of helping students build positive social values, selecting proper linguistic form and appealing to readers’ cognition in their writing procedure.