The characteristics of the gene pools of indigenous populations of Ukraine and Belarus have been studied using 28 alleles of 10 loci of biochemical gene markers (HP, GC, TF, PI, C'3, ACP1, GLO1, PGM1, ESD, and 6-PGD). The gene pools of the Russian and Ukrainian indigenous populations of Belgorod oblast (Russia) and the indigenous populations of Ukraine and Belarus have been compared. Cluster analysis, multidimensional scaling, and factor analysis of the obtained data have been used to determine the position of the Belgorod population gene pool in the Eastern Slavic gene pool system.