The main purpose of this study was to examine the competitive balance issue of Chinese Professional Baseball League, and compared the competitive balance issue about different team amount; ownership transferred and team policy of Sinon Bulls. The statistical method of Standard deviation of winning percentages was applied to compare the competitive balance during the period from 1990 to 2012. The result showed that: 1. There was greater competitive balance as the ownership of baseball club was confirmed and vice versa. 2. The competition was more imbalance as new teams joining the League. 3. The competition was more imbalance after the new policy of Sinon Bulls.