The distribution of human factor H of serum phenotypes were studied using ultrathin polyacrylamide gel isoelectric focusing (PAGIEF) and subsequent immunoblotting techniques in 203 Chinese of Han population in Liaoning Province of northeast China. The gene frequencies of HF*A and HF*B were 0.4828 and 0.5172, respectively. All the observed numbers of the phenotypes were in agreement with the expected numbers under the Hardy-Weinberg equilibrium. The gene frequencies among Chinese, Japanese, and Caucasian populations were compared.