Postacquisition control can affect acquisition performance and acquisition legitimacy plays a significant role on the relationship between postacquisition control and acquisition performance. Based on a sample of 123 acquisitions, this paper makes an empirical study on the relationship among postacquisition control, acquisition legitimacy and acquisition performance. It is found that postacquisition informal control has significant positive effect on acquisition performance and formal control has no influence on acquisition performance. Furthermore, the relationship between postacquisition formal control and acquisition performance is positively moderated by external legitimacy, while internal legitimacy has negatively moderating role on the relationship between informal control and acquisition performance.