Abstract: The frequencies of Gc subtypes of six nationalties in north China were studied by isoelectric focusing on ultra- thin polyacrylamide gel followed by the improved sulfosalicylic acid precipitation. The gene frequencies of Gc1F in Han (Harbin) , Ewenki, Tahur, M ongolian, Oroqen and Xibo nationalities were0.4246, 0.4941, 0.4479, 0.4107, 0.4606, 0.4503; those of Gc1Swere 0.2587, 0.2936, 0.3151, 0.2798, 0.3370, 0.3035 and those of Gc2 were 0. 3065, 0.2064,0.2266, 0.3006, 0.2022, 0.2388, respectively. In addition, 16 persons who had rare variant alleles of Gc (1A2, 1A6, 1A7 lA9, 1C2, 1C3, 1C4, 1C10, 2A) were found in five nationalitties.

Key words: Group-Specific Component (Gc); Genetic polymorphism; Human population genetics