Zhongrong’s book Shipin is an important work of poetics in the Southern and Northern Dynasties, which devides all 123 selected poets into three artistic kinds from the best to the relatively worse according to the three origins of their works—Guofeng, Xiaoya and Chuci. The two methods work together to form the evaluation system of Shipin. Among all the poets, Ruanji is the only one who is devided into the category of Xiaoya, which is quite special. This article tries to figure out the reason by analysing the similarities and differences between Guofeng, Xiaoya and Chuci, the relationship between Ruanji and Xiaoya, as well as compare Ruanji with Caozhi and Wangcan.