Harmony in diversity is the basic requirement of the comparative study of Chinese and foreign poetics. Expressionism, as an important school of western literature, focuses on intuition and emphasizes performance. Their works focus on the expression of emotions, using a variety of artistic means to reflect the people’s inner activities and mental state, while ignoring the description of the form of the object, often in the form of distortion and abstraction of reality. Therefore, in the works of expressionist writers and artists, abstract, deformation, symbol, illusion and so on are presented. Chinese ancient literature also attached great importance to expression, but the view of expression in expressionism literature was obviously different from that in traditional Chinese poetics. These differences are influenced not only by the time factors, but also by the national cultural differences. Through the comparative study of the two, we can find the differences and connections of expression between Expressionism and Chinese traditional poetics and promote the further development of the expression theory in contemporary Chinese literature.