This paper focuses its analysis on the dream related poems included in Wild Grass (Yecao), Lu Xun’s prose poem anthology. To start with, it studies Lu Xun’s purposes and reasons for choosing the medium called “dream” when composing poems in Wild Grass by scrutinizing the similarities between dreams and poems, and the effects that can be derived when Lu Xun’s ideas are conveyed through the form of dreams. On top of this, this paper also interprets the content of Wild Grass’ dreams and the meanings of symbols and images inside them by referring to psychological dream theories. Although literary reading on these poems may only lead to finding the superficial messages contained in Lu Xun’s dreams, such as Lu Xun’s criticism on hostile forces and the sordid social aspect or human images of that time, it is possible to discover Lu Xun’s self-examination, his sense of guilt, and his resolution for atonement, which are the key ideas of Lu Xun’s writings, based on dream theories. To be specific, due to government’s oppression of free speech, and his concern over the shock readers might get after understanding the reality of the Chinese society via reading his works, Lu Xun was obliged to tell lies in his writings. He felt guilty for this behavior and also for succeeding the feudal traditions and cultures of China. Therefore, he wandered and struggled while suffering from his guilt feeling. Eventually, he decided to expiate his guilt by vanishing with the old society and power that prevented China from being reformed. However, it was also shown from his poems that his resolution was not determined enough, that his hesitation and struggle were still not over, that he wanted to relieve himself of his heavy responsibility. Nevertheless, this inconsistent attitude of Lu Xun was merely a natural result of Lu Xun’s essence: “chaos” and “contradiction”, and it also explained why Lu Xun picked the form of dream, whose basic feature was disorder, to deliver his thoughts. As such, this study not only proves that psychological examination of Wild Grass’ dream related poems helps readers detect crucial concepts like “self-reflection,” “convincement,” and “penance” that define Lu Xun, but also proves that it is feasible and meaningful to carry out interdisciplinary or transdisciplinary research on Lu Xun’s writings.