According to Baidu Encyclopedia, Xu's surname, one of the traditional Han surnames in China, is one of the six parts of Jin State and Qing Dynasty. Xu is pronounced as "xū", which is the same as Xu. There are three theories about the origin of Xu, namely, scholar theory, classic theory and genealogy theory. Scholars say that Xu is a descendant of Hua Xushi and an ancient clan, while classics say that Xu's ancestor is Xu Chen, a doctor of Jin Dynasty, and genealogy shows that Xu is from Ji surname. History; Xu Chen is one of the courtiers of Jin State. According to scholars' research, he is the ancestor of Xu Shi family in China. Xu Chen, named Ji Zi, was rewarded for his achievements after Jin Wengong ruled the vassal. He was once sealed in a fief called Jiuji, so it was also called Jiuji.