This paper traces the history and usage of the theory of Sinicisation in western and Chinese scholarship, and discusses the intellectual trends underlying the different discourses in which the theory has been adopted. Since early 20th Century, the theory of “Sinicisation” has evolved and was adopted into three distinct historiographical discourses to construct different arguments. The first discourse is about the historical acculturation of border peoples and assimilation of domestic peoples to Chinese language, culture and economic life; the second one argues an inherent superiority in Chinese culture specifically produced cultural change across eastern Eurasia to promote nationalism; the third discourse emphasizes the diversity and mixture of the people living inside historical and contemporary China to construct and stabilise the polity. Every discourse rooted in its own intellectual trend, and also faces different criticism. Followed with examining criticisms of Sinicisation since the 1950s, this paper concludes by discussing the relationships of the three discourses of Sinicisation.