The purpose of this study change of physical fitness to season training on tennis players, the subjects of this study are selected from university athletes of 10 players. the statisics empolved in the study was pair t-test singnificance level was p<.05. the conclusion through materials of analysis was as follows: 1. the body composition was not significantly between the pre season and post season. 2. the back muscle strength(p<.01) and grasping power(p<.01) was significantly increase on post seasion when compared with pre season. 3. the flexibility was significantly increase on post seasion when compared with pre season(p<.05).4. the agility was significantly increase on post seasion(47.1±2.9) when compared with pre season(42.6±4.0)(p<.05). 5. the whol body reactivity by sound and light was not significantly between the pre season and post season. thus, details training demand specific training and professional trainer for improvement of skill.