All ancient poems are classified according to the number of words in the poem. Four-character ancient poems are referred to as four-character ancient poems for short. "Four-character poem" refers to a poem composed of four words. Four-character poem refers to a poem written in four sentences, which runs through the capital.
Four-character ancient poems have been adopted by people as early as the Book of Songs. Four-character poems are the basic genres in The Book of Songs, such as national style, Xiaoya and elegance. But it gradually declined in the Tang Dynasty, and few people wrote it.