The present study aims to examine the applications and effects of player substitution (attack, set, defend, serve) on performance outcome in university men's volleyball league in order to understand the tactics of volleyball coach during competitions. Data were collected during games of semifinal-final in university volleyball league, 2010. Descriptive statistics as well as Chi-square were used for data analysis. The results are as follows: First, the numbers of serve substitute (32.7% of total) and defend substitute (31.6% of total) were significantly higher than that of set substitute (X^2 = 100.88, p ＜ .05). Second, the effectiveness of serve substitute (39.6% of total) and defend substitute (34.7% of total) were significantly higher than that of other substitute type (X^2 = 55.98, p ＜ .05). The present findings suggest that serving and defending are the two key considerations for substitution player and the substitution of these two types of player are associated with better performance outcome. Therefore, players with higher potential could be trained for serving and defending and be substituted at the appropriate timing during competition in order to advantage the team for success.