There are various forms of Tang poetry. There are mainly five-character poems and seven-character poems in Tang Dynasty. There are also two kinds of modern poems, one is called quatrains, and the other is called metrical poems. Quatrains and metrical poems are five words and seven words respectively. Therefore, there are basically six basic forms of Tang poetry: five-character archaic poetry, seven-character archaic poetry, five-character quatrains, seven-character quatrains, five-character rhythmic poems and seven-character rhythmic poems. Classical poetry has a wide range of requirements for rhyme and meter: in a poem, the number of sentences can be more or less, the chapters can be long or short, and the rhyme can be changed. Modern poetry has strict requirements on rhyme and meter: the number of sentences in a poem is limited, that is, four-line quatrains and eight-line meter poems. The words used in each poem have certain rules, and the rhyme cannot be changed; Rhyme also requires that the middle four sentences become antithesis. The style of ancient poetry is handed down from the previous generation, so it is also called ancient style. Modern poetry has strict rules, so some people call it metrical poetry. The forms and styles of Tang poetry are colorful and innovative. It not only inherited the tradition of Han and Wei folk songs and Yuefu, but also greatly developed the singing style. It not only inherited the five-character or seven-character ancient poems of the previous generation, but also developed into a long and huge system of narrative romance; It not only expanded the use of five-character and seven-character styles, but also created modern poems with particularly beautiful and neat styles. Modern poetry was a new style of poetry at that time, and its emergence and maturity was an important event in the history of Tang poetry development. It pushed the artistic features of China's ancient poems with harmonious syllables and refined words to an unprecedented height, and found a typical form for ancient lyric poetry, which has been especially loved by people so far. However, the metrical poems in modern poetry are easy to be bound because of their strict metrical restrictions, which is a major defect brought by their advantages.