Following the Book of Songs, in the 4th century BC, a new style of poetry appeared in the State of Chu, called Songs of the Chu, and its founder was Qu Yuan. Later, the Han people compiled the works written by Qu Yuan, Song Yu and others into a book called Songs of the South. The Songs of Chu broke through four sentences in the Book of Songs and developed into five-character sentences and seven-character sentences, that is, even sentences (four words in a sentence) were changed into odd sentences (five words in a sentence and seven words in a sentence), which not only better expressed thoughts and feelings, but also made the rhythm and rhythm more musical.
In the Han Dynasty, Yuefu Poetry, a poem sung with music, appeared. There are four words, five words and miscellaneous words in language, but most of them are five words. Later, the literati headed by Cao Cao and his son and Tao Yuanming developed five-character poems. At the same time, seven-character poems have also developed greatly.