In the late Han Dynasty more than 1,500 years ago, in the southwest border far away from the rule of the feudal central dynasty, there was a local dynasty of the Cuan family in Nanzhong that lasted for more than 500 years. His sphere of influence included all of modern Yunnan. border, southern Sichuan, eastern Guizhou and parts of northern Vietnam. The local dynasty of the Cuan family ruled Luliang, the political, economic and cultural center of Nanzhong. The dynasty of the Cuan family also cultivated virtues and cultivated literature, creating a splendid local culture - Cuan culture. Historical books rarely record this period of history, which casts a mysterious veil on the Nanzhong Cuan family. Today, only the well-preserved "Cuan Longyan Monument" still silently tells the glory of that year. The "Cuan Longyan Monument" was erected in 446 AD. In 1961, it was announced by the State Council as one of the first batch of national key cultural relics protection units. This stele has important research value in terms of shape, content, history and calligraphy. The inscription records the glory of the Cuan family, the spread of Han culture in Nanzhong and the integration of various ethnic groups in Yunnan; the style of writing has the style of the Wei and Jin Dynasties, with smooth and smooth parallelism; the calligraphy of the inscription is unique and unique in the history of Chinese calligraphy, and its calligraphy form is known as It is Cuan style and has been highly praised by calligraphers of all dynasties. Kang Youwei called it "the most regular script in regular script", "the best official script in ancient and modern times" and "the first in divine quality". It is a precious material for studying the evolution of Chinese calligraphy.