The purpose of this study is to investigate the effect of rope jumping training on the health related physical fitness of mental retardation students. The 9 13-15 year-old students with Mental Retardation from the Special Education Section of Chung-Shan Junior High School examined, divided into experimental and control groups of 6 and 3 members using and random assignment respectively. The experimental group was given the 45 minute rope jumping training, twice a week, for 12 weeks, with exercise intensity estimated by using the rating of perceived exertion (RPE) ranged from easy (11) to tired (15). On the other hand, the control group kept the regular activities. All participants were requested to examine their health related physical fitness before and after training. The analysis is conducted by dependent samples t-test and analysis of covariance (ANCOVA). The important results of the study are summarized as-follows: (A) Dependent samples t-test is used to analyze the difference in the two groups between pre-and post-training. There is a significant difference in muscular endurance, flexibility and cardiopulmonary endurance in the experimental group analyzed with ANCOVA (p<.05). (B) There are significant differences in muscular endurance, flexibility and cardiopulmonary endurance in both groups (p<.05). This study suggests that the rope jumping training for 12 weeks has a great improvement in the flexibility and aerobic capacity of Intellectual mental retardation students.