本文對於朱子與陽明的孟學詮釋做一比較，比較其間的詮釋之差異。朱子學以《大學》為架構，通貫地詮釋四書，故對於孟子學的詮釋，也是大學化，如知言、養氣，成了格致與誠意，而有其先後之序；而盡心、知性，也成了先知性（物格）然後盡心（知至）。除此之外，朱子以理氣論詮釋孟、告之辯，對於性的認定，朱子認為孟子的理解是對的，因為視性為理；而告子之不知性，在認性為氣。這些是朱子詮釋孟子的大要。而陽明以良知學詮釋孟子，視良知為義內，反對朱子的格物於外的講法，視朱子學為義外。於孟子的「盡其心者章」中，以「生知安行，學知利行」等說法比配孟子；還有詮釋孟子性善，視之為即理即氣，而不是如朱子的性只是理之義。此二派（心學與理學）對於孟子學的詮釋進路有所不同，在此吾人一一論及之，並評斷之。

This study compares interpretation of Zhu Xi and Yang-Ming on Mencius theory. Theory of Zhu Xi was based on Da Xue and it thoroughly interpreted the Four Books. Hence, the interpretation on Mencius theory was upon Da Xue. For instance, Zhiyi and Yangqi become Gezhi and Chengyi and there is sequence. Jinxin and Zhixing refer to first Zhixing (Wuge) and then Zhixing (Zhizhi). In addition, Zhu Xi interpreted debate between Mencius and Gaozi by Li Chi theory. Regarding nature, Zhu Xi agreed with Mencius since they treated nature as reason. Gaozi did not agree with Zhixing and he treated nature as Chi. It is the basic interpretation of Zhu Xi on Mencius. Theory of Yang-Ming explained Mencius by theory of conscience, regarded conscience as Yi Nei and opposed Gewu Yu Wai of Zhu Xi and treated theory of Zhu Xi as Yi Wai. In Mencius’ “chapter of Jin Qi Xin Zhe”, “Sheng Jin An Xin, Xue Zhi Li Xin” is compared to Mencius. Besides, Mencius’ good nature is treated as reason and Chi instead of suggestion of Zhu Xi that nature is reason. The two schools (theory of mind and theory of reason) interpret Mencius theory differently. The author analyzes and comments on them.