The allele frequency distribution of seven microsatellite loci of the nonrecombining region of the Y chromosome (Y-STRs) was analyzed in three geographically distant indigenous populations of the Tuva Republic. The populations did not differ in allele frequency distribution of the seven Y-STRs. The Y-chromosome microsatellite loci in Tuvinians showed a high diversity (H = 0.575) that was nearly identical in all three populations. The genetic distance Ddm between the three populations was low, suggesting no subdivision of the modern male population of Tuva. Estimates of the period of linear changes in Ddm showed that Y-chromosome microsatellites can be used to reconstruct evolutionary events dating back no more than 40,000-50,000 years. The problems of human population phylogeny are discussed on the basis of data on Y-chromosome STRs.