Abstract: Why Cheng Hao and Cheng Yi emphasized the concept of Jing(“敬”) and explained its basic meaning with Zhuyi(“主一”) is an important topic in the history of philosophy.In addition to the exposition of the importance of Jing in Lun Yu and Zhou Yi,as a must read book for scholars in the early Song Dynasty,the viewpoint of Kong Anguo in the Commentary on Lun Yu that “Jing is the most important way to achieve Ren(‘仁’)” may have become an important source of inspiration for Cheng Hao and Cheng Yi to make Jing the core of their theory.In addition,the original meaning of Zheng(“正”) is “Behavior is about achieving a single goal”,which is likely the source of Cheng Yi’s exegesis of Zhuyi;Moreover,Cheng Hao had already clearly proposed and repeatedly emphasized the idea of Jing and the uniqueness of Tianli(“天理”),which became the reason why Cheng Yi later explained Jing with the concept of Zhuyi.