The purpose of this study was to investigate the effects of core-muscle training on volleyball serving stability. The subjects are 36 volleyball players of National Yuanli Senior High School in Miaoli County. After a four-week training, the collected data was analyzed by SPSS for Windows. The results of this study showed that after a duration of four-week training, the experimental group shows significant improvement comparing to the control group in Isometric abdominal muscle endurance, isometric back muscle endurance, dynamic back muscles endurance, and the fixed standing serving and jumping serving are improved as well. But there is no significant difference in dynamic abdominal muscle endurance.
