PURPOSE: This study explored how serve skills affect the results of the games in the 25th Universiade (World University Games), held in Belgrade in July 2009, organized for university athletes by the International University Sports Federation (FISU). METHOD: Data were collected based on the tennis players who were in round of 32, and the raw data were collected from the official daily bulletin. This study uses independent sample t-test analysis of the statistical test and the Pearson product moment correlation analysis. The identification of significant level was that α<.05 up to the level of significance. RESULTS: 1. In terms of serve variable factors, first serve winning rate, second serve winning rate and somehow scores of men and women winning players were significantly better than the defeated player. In addition, male athletes in ACE ball significantly superior on the losing players. 2. In terms of the relation between serve variable factors and total scores, first serve winning rate and ACE balls are significantly related to total scores. Besides, the second serve winning rate and total scores of male athletes also showed significant correlation. CONCLUSIONS: 1. The study found that the first serve winning rate, the second serve winning rate and total scores of male and female outstanding tennis player in the world university are significantly better than losing players. The result shows both serve variables affect of tennis. 2. The ACE balls of male athletes are much better than the defeated players, and this factor may become the key factor which affects the outcome of male athletes. 3. The results also show that in terms of the relation between the serve variables of male and female players and their total scores first serve winning rate and ACE balls are significantly related to total scores. Therefore, serve skills is really important key factor in the results of total scores.