C3 allotyping was performed on 523 unrelated Korean. No C3*F and rare variants were found in this population. This result was similar to those found in other Asian populations. The gene frequencies for the common C3 alleles distributed differently with the racial background: In Caucasoids C3*F showed relatively high frequencies (0.140-0.273). But C3*F was very rare for Mongoloids (0.000-0.006) of Korean, Chinese, and Japanese. The Negroids and Eskimos showed a range of 0.056-0.070 C3*F allelic frequencies which were intermediate figures from Caucasoids and Mongoloids.