Data from marriage records of the city of Belgorod for 1960, 1985, and 1995 have been used to calculate parameters characterizing migration in the Belgorod population. The marriage migration coefficients (m) in these years were 0.83, 0.68, and 0.58, respectively, and the endogamy indices were 0.05, 0.13, and 0.22, respectively. The marriage convergence (K) with respect to birthplace in the same years were 0.15, 0.13, and 0.14, respectively. In the period studied, spatial parameters reflecting the genetic efficiency of migration increased. The mean migration distance also increased; it was 430, 667, and 926 km in 1960, 1985, and 1995, respectively. The migration distances for men and women in the same years were 477, 725, and 986 km and 383, 609, and 866 km, respectively. The radius of the Belgorod population in terms of Malecot's isolation by distance model increased in the period studied (55, 81, and 95 km in 1960, 1985, and 1995, respectively). The parameter b in that period decreased (0.00110, 0.00074, and 0.00062, respectively), which indicates a decrease in the inbred component. The increase in marital distance (590, 796, and 891 km in 1960, 1985, and 1995, respectively) indicates a steady increase in the outbred component of the population.