Understanding where the mutual fund returns come from may be advantageous to construct a portfolio of managers for a fund. This paper uses mutual fund performance data in China market from 2001 to 2018 to study whether differences in manager’s former working experience affect their performance. After regressions and bootstrap tests, there come some conclusions: managers who starting careers as buy-side industry and sell-side macro analysts generate significant excess returns of 0.4% and 0.6%. What’s more, there is no evidence that portfolio managers have market-timing abilities. Last but not least, industry groups show larger portions of return from small-cap stocks and growth stocks. Specifically, buy-side industry group shows superior ability in picking up promising small-cap stocks, and sell-side industry group tends to pay most attention to and invest more in growth stocks.