Abstract <p>The article presents the results of the analysis of the variability of the level of random inbreeding and the “family portrait” of the population of Belgorod oblast from 1999 to 2019. A decrease in the population (over 18 years old) of Belgorod oblast (by an average of 12%), the number of surnames (by an average of 34%), and the migration influx of population (by an average of 4.8 times) was established with an increase in the level of random inbreeding (on average from 0.00044 to 0.00054) over 20 years. There is a tendency towards increasing internal subdivision and uniqueness of the “family portrait” of districts located on the outskirts of the oblast. Over the past 20 years, there has been an increase in the dependence of the <i>F</i>_st level of the population of Belgorod oblast on such population parameters as the number of surnames (by 2.8 times), the level of migration influx of population (by 1.2 times), and the degree of development of the transport network (by 1.6 times), while the connection with the geographical distance from the regional center has been leveled out.</p>