Classification reflects the the degree and standard of understanding to things. It is the angle and attitude to value things and reflects the depth and width of understanding things. There are different ideological trends in different dynasties. LIU Xiang

LIU Xin and Ban Gu had reasonable justification of the classification of Fu and Song Poetry in Poetical Category of

Han Shu : Yi Wen Zhi.

This thesis bases on BAN Gu’s Poetical Category of

Han Shu : Yi Wen Zhi

and Liang Du Xu Fu to research and study then compare with The Book of Songs

finally finds out the standard of classification of Fu and Song Poetry. This standard doesn’t lie on the mode of transmission or literary and artistic form. It is the modeling to ancient laws and regulations of sage kings. Song poetry inherits Guo Feng in The Book of Songs which is collected from citizens and can know the advantages and disadvantages of politics. Fu inherits Ya and Song in The Book of Songs which is created by officials aiming to supervise politic system. This is exactly the meaning of BAN Gu’s words. He said Fu developed from ancient poetry.