Abstract: The genetic polymorphism of the fourth complement component (C4) in Uigur, Miao, Yaoand Zhuang Nationalities in China was investigated using the methodsrecommended by thte4th International Workshop for the Genetics of Complement and the advanced techniques oflaser densitometry scanning, and compared with the data of Han Nationality prlviously deter-mined by us. As to C4, the frequency of C4A3 was found as the highest among five nationalities; the remaining frequencies orders were C4A2, Q0, 4, 1 successively among four nationalities except for Uigur. As to C4B, the frequency of C4B1 was found as the highest among fivepopulations; the remaining freq?encies orders were C4B2, Q0, 3 in Han and Uigur, 92, Q0,2, 3 in Miao and Zhuang, Q0, 2, 92 in Yao respectively. The differences among five populations were focused on allotypes of C4A2, C4B2, C4AQ0 and C4BQ0. The differences of C4genetic frequencies among Chinese Han, Japanese, Caucasian, and Negroid were also discussed.

Key words: Complement C4; Genetic polymorphism; Human genetics