Qu Yuan (340-278 BC), a representative poet in the 4th century BC, and his contemporaries, produced their own type of songs, a representative collection of which was compiled under the name of Chu Ci (literally, poetry of the Chu Kingdom).

Qu Yuan wrote many excellent poems in his life, a large number of which were composed in his exile. The style of Qu Yuan's poems is different from that of The Book of Songs (Feng), the most significant segment of The Book of Odes. Qu Yuan's poems are called Poetic Prose of Chu, or the Sao-Style Poetry, in the history of Chinese literature.

The Sao-Style Poetry is characterized by feature length, flexible form and having an auxiliary word pronounced as Xi at the end of most lines. Compared with poetry before the period of Qu Yuan, the Sao-Style Poetry created by Qu Yuan has the following additional features: (i) in terms of sentence pattern, the Sao-Style Poetry broke away with the previous four-character pattern, and mainly adopted six-character lines, intermingled with five-character and seven-character lines; (ii) in terms of innovations in composition, the Sao-Style Poetry broke the confines of ancient poems, but gave loose to the author's feeling, either narrating, sadly chanting or lamenting, and had a clear structure with the beginning and development of plots; (iii) in terms of the system, poems before were only short ones with over ten or tens of lines, while Lament on Encountering Sorrow written by Qu Yuan was made up of 2,496 characters in 372 lines, laying a foundation for the feature-length system of Chinese ancient poetry.