"Theory of Soul" is a poetic creation and critical concept in China's ancient poetics, which was strongly advocated by Yuan Mei in Qing Dynasty. It, together with verve theory, mode theory and texture theory, is called one of the four major poetic theories in the early Qing Dynasty. It is generally believed that Yuan Mei's theory of soul is his poetic theory. In fact, it is the inheritance and development of the poetic theory of "expressing one's own spirit and not sticking to one pattern" represented by the public security school in Ming Dynasty (Yuan Hongdao's Preface to a Little Poetry). The core of the theory of soul is to emphasize that poetry creation should directly express the poet's thoughts and feelings, and that the essence of poetry is lyric and the natural expression of human feelings.