Abstract: Objective To investigate the genetic polymorphisms of 18 autosomal short tandem repeats （STR） loci in Changsha Han population, and explore the population genetic relationships and evaluate its application value in forensic medicine. Methods The DNA of 2 004 unrelated individuals in Changsha Han population were amplified using Goldeneye?誖DNA ID System BASIC, and the PCR products were analyzed by electrophoresis using 3130xl genetic analyzer. The fragment sizes of alleles were analyzed subsequently by GeneMapper?誖ID v3.2. The frequency data and forensic genetic parameters ［observed heterozygosity （Ho）, expected heterozygosity （He）, power of discrimination （DP） and polymorphic information content （PIC）］ of 18 STR loci were statistically analyzed. Total probability of discrimination （TDP）, probability of exclusion in trio cases （PEtrio） and probability of exclusion in duo cases （PEduo） were calculated by Cervus 3.0. Hardy-Weinberg equilibrium and linkage disequilibrium of the loci were detected by Arlequin v3.5. The results were compared with the available data of other populations from different races and regions. Results The power of discrimination （DP）, and the polymorphic information content （PIC） of each locus of Changsha Han population ranged from 0.783 6 to 0.987 9 and 0.549 4 to 0.914 5, respectively. The TDP, cumulative probability of exclusion in trio cases （CPEtrio） and cumulative probability of exclusion in duo cases （CPEduo） were 0.999 999 999 999 999 999 999 865 2, 0.999 999 979 and 0.999 988 325, respectively. According to the Nei’s DA genetic distance, the genetic distance between Changsha Han and Hunan Han populations was the smallest （0.014 1）, while it was the largest （0.041 8） between Changsha Han and Xinjiang Kazakh populations. Conclusion The 18 STR loci shows abundant genetic polymorphisms in Changsha Han population. The study of genetic diversity among different populations has an important meaning for the research of their origins, migrations and their relationships.

Key words: forensic genetics, polymorphism, genetic, short tandem repeat, autosome, genetic distance, Han population, Changsha