Abstract: Objective To investigate the polymorphism and forensic efficiency values of STR loci D12S391?D18S865 Methods Population studies on D12S391 and D18S865 were carried out in a sample of 454 unrelated Wenzhou Han individuals using PCR followed by PAGE and silver stain detection. Results 11?7 alleles and 50?21 genotypes of D12S391?D18S865 were respectively observed among the 454 unrelated individuals. The genotype frequency matched the Hardy- Weinberg equilibrium, The heterozygotes(H) in D12S391?D18S865 were 0.797 4? 0.737 9, Power of Exclusion were 0.956 6? 0.907 7, polymorphism information content(PIC) were 0.826 0? 0.727 9 respectively. Conclusion D12S391 and D18S865 were high polymorphic loci and the frequencies were in accordance with Hardy-Weinberg equilibrium(P>0.5),so the two loci can be used in forensic medicine and in other genetic research areas.

Key words: genetic polymorphism, short tandem repeats, polymerase chain reaction