The investment style drift is a double-edged sword, which can not only produce short-term excess returns but also reflect huge risk behind it. Due to the fact that China’s fund information disclosure system is not perfect currently and is lack of adequate regulatory work as well as the fact that many investors focus on earnings and ignore the risk, the phenomenon of fund’s investment style drift is widespread. Selecting 65 partial stock funds which started before July 2004 as samples, this paper makes identification on the actual investment style of sample fund during the period of 2005—2012 and has an examination on the relationship between past performance and future style drift. We have the following findings: (1) There are serious investment style drift and the drift changes significantly with the market trend. Besides, the investment style of funds is in convergence obviously.(2)In terms of value/growth style drift, most of the fund investment styles tend to grow and balance, which illustrates the lack of value investment.(3)In terms of large/small cap style drift, investment styles in larger/small cap are even. The investment style changes with the market trend in some years, style drift is in convergence obviously.(4) The better the fund performance in the past, the more prone to investment style drift in the future. However, investment style drift can not bring the improvement of fund performance.