In the developing Chinese capital market which dominated by individual investors and potentially suffer from more behavioral biases, we simultaneously examine the trading and monitoring role of mutual funds (as the largest institutional investor in China) in corporate acquisition activities where there are potentials for a wide disparity of interest between institutional investors and controlling shareholders. We find the level of holding by all mutual funds is not a superiors indicator of deal quality, there are some evidence that the collective holdings by the largest fund management companies positively relate to the deal quality and they potentially play the monitoring role in M&A event. Our paper contributes to the existing literature that “transient investors” can also gain from monitoring in the market where institutional investors has less dominant position.