This research aims to determination effect of changing coach on team’s performance in the Iran’s Football Pro-League during season. The method applied in this research is causal-comparative. The participants in this research were all the 54 teams in Iran’s pro league during three seasons (2008-09, 2009-10, 2010-11) and 30 teams which changed coaches were chosen as a sample. Variance analysis results showed that changing coach had no effect on team’s performance in none of 1, 2, 4, 8, 10, 12, 16, 18, 20 games before and after changing coach (p<0.05). Changing coach in short term had a few effect, and had no effect in long term on team performance (p<0.05). It seems that changing coach is not the only option to improve team’s performance. Other elements like player’s motivation, on time salary reception, rewards, player’s quality, referee’s quality and etc. can affect team’s performance.