The purpose of this study was to investigate the relationship between leisure motivation and leisure involvement in slow pitch amateur players, and to examine the influence of leisure motivation on leisure involvement. The population was 800 softball league tournament players, and 560 were recruited in randomly selected assessment to 532 completed by the participants. All of the collected data has been analyzed by using Pearson product-moment correlation analysis and multiple stepwise regression analysis. The results indicated that the relationship between leisure motivation and leisure involvement in all dimensions was significantly correlated, and the intrinsic motivation, identified regulation, and introjected regulation can positively predict attraction, centrality, and self-expression. The external regulation and motivation can negatively predict those. The concluded that the self- determination will regulate feelings of participation involvement, the higher the activities of its higher perceived value, is relatively lower. The recommend that the participants should be using high self-determined motivation to guide decision related behavior patterns.