Si Kongtu in late Tang Dynasty. There are differences between later generations and Zhong Rong's poems, so Twenty-four Poems are called Si Kongtu's poems. There are 24 types of poetry: vigorous, diluted, delicate, thoughtful, quaint, refined, vigorous, beautiful, natural, subtle, bold, spiritual, meticulous, wild, strange, tortuous, realistic, sad, descriptive, super-conceptual, elegant and broad-minded. Each product is illustrated by twelve four-character poems, so it is not only a poem about poetry, but also a poem with perfect artistic conception. In the arrangement of twenty-four categories, Sun Liankui's poem "Speculation" says: "Boldness is the end of flow, and flow is the symbol of boldness. All the products in the middle are born of "male mixed", so what does "flow" do? " Yang Tingzhi's A Brief Interpretation of Twenty-four Poems also said: "Poetry begins with" profundity ",takes the whole article as a whole, is infinite and taiji", and ends with "flow", "it changes without staying here, and the flow is wonderful, such as the length of heaven and earth, taiji is infinite". The first and last echoes of "Hunhun" and "Flowing" opened the understanding of the universe ontology by poetry and Taoist philosophers, and clarified the relationship between Tao, things and the beauty of poetry on the ontology of the unity of man and nature, thus elevating the Book of Songs to the philosophical level. Si Kongtu discussed poetry with such a broad world view, and attributed poetry creation to a natural combination of subjective and objective, that is, "the harmony between thinking and environment", and put forward the creation centered on "image" and the critical theory centered on "verve". Si Kongtu's poetic theory is based on "lasting appeal", which refers to "meaning beyond rhyme" and "meaning beyond taste". Specifically, it means "being near but not floating, being far and inexhaustible, you can express the meaning beyond rhyme" and "knowing the meaning beyond taste when you work all over the United States" (Talking about Poetry with Li Sheng), which further develops Zhong Rong's "taste". Of course, poetry has the meaning of "quality", "character" and "quality", and 24 poems are really "quality" If similar products are classified into one category, these 24 products can be summarized into three categories: simple beauty, magnificent beauty and gorgeous beauty. Simple beauty includes thirteen products such as dilution, elegance, exquisiteness, naturalness, implication, wildness, strangeness, truthfulness, transcendence, elegance and broadness. Magnificence includes five products: vigorous, vigorous, bold, sad and elegant; Beauty has six aspects: slim, beautiful, spiritual, meticulous, thoughtful and descriptive. It can be seen that Sikong Tu attaches importance to plain beauty, the essence of which is truth, quietness and elegance, which is the historical projection of the transformation of China's ancient aesthetic theory from magnificent beauty to plain beauty after the middle Tang Dynasty. Due to its vague words and far-reaching meanings, Shi Pin has always had different interpretations, but as an epoch-making poetic work, Shi Ji deserves its "profound understanding of poetic theory".