English writing, as a basic language skill for second language learners, is being paid close attention to. How to achieve better results in English teaching and how to develop students’ writing competence remain an arduous task for English teachers. Based on the review of the concerning literature from other researchers as well as a summery of the author’s own experimental research, the author of this essay for the first time tries to give definitions of the process approach to writing, make a comparison between product and process approach to teaching writing and accordingly make suggestions about the basic principles of teaching writing with the application of the process approach. With this understanding of the process approach to writing, the author focuses on a discussion about the two classroom teaching models by using the process approach, namely teaching models with minimal control and maximal control to different English level students. Experimental study shows that the subjects were all making significant progress in their writing skill.