Adequate cardiopulmonary resuscitation (CPR) skill is essential in improving survival rate of sudden cardiac arrest (SCA). However, the skill deteriorates rapidly following CPR training. We developed a computer game by using 3-Dimensional virtual technology (3-D CPR game) for laypersons in the purpose to improve skill retention. As the testing phase, a randomized control trial, in which we recruited 97 freshman medical students who had no prior CPR training experience, was used to test its effect on 3-month CPR Skill retention. The usability of the game was also tested using a 33 item questionnaire rated with 5-point Likert scale. Three months after the initial CPR training, the retention rate of CPR skill in the game group was significantly higher compared with the control (p<0.05) and the average score on 4 dimensions of usability were 3.99-4.05. Overall, using 3-D CPR game in improving CPR skill retention is feasible and effective.