This thesis attempts to study the theory of Cheng of Xunzi from a perspective of spiritual exercises. In the Warring States period, the theory of ”arts of governing Qi & cultivating mind” of Xunzi was a typical representative of Confucian spiritual exercises. As a way of spiritual exercises (mind cultivation), Cheng takes moral cultivation as its ideal and aim. In addition, in the context of the theory of naturalism human nature, the idea of Cheng has a special theoretical significance in the theory of moral cultivation. Especially, this paper pointed out that ”Cultivating Mind with Cheng” make it possible for mind to translate itself into pure moral rationality eventually through this spiritual exercises process. Finally, the analysis of the practical process of Cheng shows that Cheng can enable one to concentrate his attentions in the mind on the cultivation of moral rationality, and this can provide the subject basis for the moral self-cultivation practice of ”governing nature with mind”.