Objective To explore the effects of CPR educational games on CPR knowledge acquisition and retention in nursing undergraduate students, and to provide reference for improving CPR teaching effect. Methods A total of 100 nursing undergraduate students enrolled in 2016 were randomized into a control group and an intervention group, with 50 students in each group. In the CPR teaching, the traditional teaching method was used for the control group, while CPR educational games were utilized for the intervention group. At 1 week after the teaching, CPR-teaching related knowledge acquisition of the two groups were assessed, and their knowledge retention in the 3rd, 6th and 10th months of clinical practice were evaluated. Results The total theoretical examination score and comprehensive ability assessment score of the intervention group were significantly better than those of the control group (P<0.05 for both). The trend prediction analysis of knowledge retention showed that, the students′ knowledge retention presented a tendency of decrease, then it entered into a stable stage after 6 months of decreasing, and then it showed a descending tendency after the 10th month. Conclusion Application of the CPR educational games in CPR teaching for undergraduate nursing students, is benefit for their CPR knowledge and skill retention continuously, thus it can be used as an auxiliary educational method for CPR nursing education, and it is suggested to retrain CPR for the students at the 6th month.