Li Dezhang, a native of Yongchang (Longyang, Baoshan) in the Ming Dynasty, was once an official in Jishi Shu, imperial academy, and was later demoted as a jewelry and jade supervisor in Beijing. Once there was a fire in the palace, he found that the melted pearl jade was crystal clear after being watered and solidified. After returning to his hometown, he made "Yongzi" with raw materials such as south red agate, jade and amber, which are rich in the local area. Li Dezhang was born in the 16th year of Chenghua (148 1) and died in the 19th year of Jiajing (1540) at the age of 59. In the seventh year of Zheng De (15 12), Yongzi was invented, and in the eighteenth year of Jiajing (1539), Yongzi was pardoned as a tribute.