Objective: Discuss the effect of cooperative learning theory on ICU nursing teaching for the clinical undergraduates. Method: Take 21 undergraduates majored in nursing who practiced in the nursing section for the serious diseases in this Hospital during January, 2013April, 2013 as the contrast group, take 22 undergraduates majored in nursing who practiced in the nursing section for the serious diseases in this Hospital during January, 2014April, 2014 as the observing group. Traditional clinical nursing teaching method is used in the contrast group while cooperative learning theory teaching method is used in the observing group, and the teaching effect is compared between the two groups. Result: After experiment is finished, there is statistical significance of the comparative difference on basic nursing theoretical knowledge, basic nursing skills and practical nursing ability of the two nursing undergraduates. Conclusion: Compared with traditional teaching method, cooperative learning is helpful to improve ICU clinical nursing teaching quality, which can be better and more effective to initiate the learning activity and enthusiasm of the students, and can be more conducive to promote the communication ability, problem solving ability, selflearning ability, cooperative ability and team spirit cultivation among the students so that this method can improve the basic nursing theoretical knowledge, basic nursing skills and nursing practice ability of the nursing undergraduates, which is worth clinical promotion.