Abstract: To analyze the genetic polymorphism of 7 STR loci (D12S1718，D12S1675, D12S358, D12S367, D12S1638, D12S1646 and D12S1682) on chromosome 12 in Shaanxi Hans. EDTA-blood specimens were collected from 80 unrelated individuals from Chinese Han population in Shaanxi province. The DNA samples were extracted and relevant fragments were amplified by polymerase chain reaction (PCR). The PCR products were analyzed by ABI 3100 Genetic Analyzer. The number of alleles and genotypes observed at loci D12S1718, D12S1675, D12S358, D12S367, D12S1638, D12S1646 and D12S1682 were 7, 10, 8, 8, 6, 9, 11 for alleles and 10, 17, 18, 18, 14, 18, and 26 for genotypes, respectively. The heterozygosities for the 7 STR loci were 44.28％, 66.10％, 78.89％, 77.89％, 73.69％, 74.55％ and 82.39％, respectively. The distribution of allele frequencies of 7 STR loci on chromosome 12 was consistent with Hardy-Weinberg equilibrium and relatively high genetic polymorphism was observed in Shaanxi Han population.