According to Sui Shu Jing Ji Zhi and relevant materials, in the historial cause of cultural academical development in Wei Jing Nan Bai Periods, due to the developed discrimination of writing types and gradual distinction of the intention and extention of fu, fu develops into an independent writing type differentiated from such writing types as sao, qi, song, etc., and is separately recorded by catalogues. Fu documents are sorted out and studied on a remarkable scale. Compared with the theoretical discussion in the Han Dynasty, studies of fu becomes systematical and rich in materials during the periods. |