Abstract: There are two aspects in the theory about temperament of Sun Yuanxiang: Firstly, he proposed to express one's feeling as really as possible in one's poem just as Yuan mei did; secondly, he proposed incompatibly that the expression of one' s temperament in one' s poem could never go too far beyond the Confucian morality, just as Jiang Shiquan did. The style of his poem is consistent with his theory. His style is more inclined to Yuan Mei in writing. Most of his poems show his own feeling, much more emotional and as less rational as he proposed in his theory on temperament.