This study assessed the usefulness of geographic and pairwise genetic distances in the characterization of five sheep populations using 15 microsatellite markers. The average F statistics across loci were F (IT) = 0.523 +/- 0.140, F (ST) = 0.363 +/- 0.131, and F (IS) = 0.263 +/- 0.092. The average heterozygosity was 0.716 +/- 0.069, polymorphism information content was 0.691 +/- 0.070, and effective number of alleles was 3.736 +/- 0.998. Sheep populations clustered into group 1 (Hu and Tong breeds) and group 2 (small-tailed Han, Wadi, and Tan breeds). Reynolds' distance varied from 0.0062 to 0.0499, and the range of gene flow (N (m)) was 4.8834-40.0726 among the sheep populations. The results showed that the genetic structure of the five populations was not consistent with their genetic distances, and the population genetic divergence was not linearly related to geographic distance as indicated by a Mantel test (P = 0.7936).