Confucian thought has been much preoccupied with li (「禮」) as a means for the realization of the ideal of dao (「道」). Li is a rich and fluid notion with a long history of evolution. In the Analects and Mengzi, the inner aspect of the li-performance pertains to ren (「仁」), embracing a variety of moral attitudes, dispositions, and emotions, whereas the outer aspect pertains to the underlying vision of the unity and harmony of humanity and tian (「天」). Which means, both Analects and Mengzi consider moral ethics as an autonomous ethics of virtue. However, Xunzi takes li-performance as the result of conscious activity wei(「偽」). In Xunzi, an explicit concern with rational coherence in ethical discourse, in particular an emphasis on the unity of ren, li and yi (「義」). The essay will aim at analyzing the evolution and functions of li towards Mengzi and Xunzi.