In foreign affairs sponsored by the Lifanyuan，Sino-Russian relationship played an important role，such as the supervision and management of Sino-Russian trade. Not only covering the boundary disputes，fugitive issues and Dzungar Mongolia controversies，the Sino-Russian relationship also comprehensively contained the Qing court's strategy to control Khalkha Mongolia，which was carried out in the management of Sino-Russian trade by the Lifanyuan. Based on the supervision and management of Sino-Russian trade by the Lifanyuan，this paper focuses on its performance and real role. In addition to exploring the change of Qing government's policy towards Sino-Russian trade，it evaluates the diplomatic role of the Lifanyuan and discusses the gradual control on Khalkha Mongolia by the Qing government．