This paper covers an experimental study with the application of cooperative learning in the college English teaching to vocational students. It intends to find answers to the following questions: how do students cooperate in cooperative learning? Can cooperative learning promote students' learning? The author conducts an experiment by applying recording. Based on the above research work, this result has been reached: cooperative learning can promote students'mastering of vocabulary and grammar. The author would like to share her experiences with others in pedagogical studies of teaching vocational college students English.