Corporate site visit becomes more and more significant for investors to acquire firm information. Starting from 2009, the Shenzhen Stock Exchange (SZSE) regulates all listed firms by requiring them to reveal information on corporate site visits of investors such as when and where and in what form the firms received site visits in their annual reports, which provides us a experimental basis to deeply explore how investors' corporate site visits is related with firms' earnings management. Making use of the particular dataset of investors' corporate site visits to listed firms on SZSE during 2012-2017, we explore how investors' corporate site visits impact firms' earnings management. Applying the modified cross-sectional Jones model (1995), modified Dechow-Dichev model (2002), and Roychowdhury model (2006), we come to the conclusion that investors who conduct corporate site visits will reduce firms' incentive to manage earnings management in terms of both accrual and real-based. Furthermore, we discover a phenomenon corporate site visits play an significant part in corporate external governance for larger firms and newer firms. Corporate site visit can be an effective supplementary measurement to improve corporate external governance for larger firms and newer firms. We hope by presenting evidence on investors' corporate site visits can reduce firms' earnings management, firms can find systematic ways to improve its internal governance ability. In addition, by showing the informative role of corporate site visits, investors can make more accurate investment decisions. Overall, on one hand our empirical results indicate investors' corporate site visits can effectively mitigate agency problem and contribute to study on corporate governance, on the other hand, the results can provide helpful information for policy-makers, scholars, firms and investors. Keywords: corporate site visits, accrual and real-based earnings management, corporate governance, information acquisition, agency problem