The philosophical system of Zhang Zai includes rich thinking concerning the mind,which differs from that of Lu Xiangshan and Wang Yangming. Given the paucity of scholarly interest in Zhang Zai’s theory of mind,this paper will,of necessity,take Zhang Zai’s three mental propositions as its horizon of observation,taking the basic problems of his thought as the main line,constructing an outline from three particular aspects,and explaining them: first,it will explore the three propositions of his theory of mind; second,the morphological division of the relationship between "mind"and "thing"; and third,the theoretical basis of this relationship.Finally,the philosophical characteristics,historical influence,and modern significance of Zhang Zai’s theory of mind will be summarized.