Abstract: Objective To investigate genetic polymorphisms of 21 non-CODIS STR loci in Han population from the east of China and to explore their forensic application value. Methods Twenty-one non-CODIS STR loci, were amplified with AGCU 21+1 STR kit and DNA samples were obtained from 225 unrelated individuals of the Han population from the east of China. The PCR products were analyzed with 3130 Genetic Analyzer and genotyped with GeneMapper ID v3.2 software. The genetic data were statistically analyzed with PowerStats v12.xls and Cervus 2.0 software. Results The distributions of 21 non-CODIS STR loci satisfied the Hardy-Weinberg equilibration. The heterozygosity（H） distributions were 0.596-0.804, the discrimination power（DP） were 0.764-0.948, the probability of exclusion of duo-testing（PEduo） were 0.176-0.492, the probability of exclusion of trios-testing（PEtrio） were 0.334-0.663, and the polymorphic information content（PIC） were 0.522-0.807. The cumulative probability of exclusion（CPE） of duo-testing was 0.999 707, the CPE of trios-testing was 0.999 999 4, and the cumulated discrimination power（CDP） was 0.999 999 999 999 999 999 94. Conclusion Twenty-one non-CODIS STR loci are highly polymorphic. They can be effectively used in personal identification and paternity testing in trios cases. They can also be used as supplement in the difficult cases of diad paternity testing.

Key words: forensic genetics, polymorphism, genetic, short tandem repeats, paternity testing