Abstract: Objective: To explore polymorphism and forensic application by detecting 27 STR locus simultaneously. Method : The DNA of the samples was extracted by magnetic beads, amplified with PowerPlex ? Fusion 6C amplification Kit with 6-dye fluorescences labeling, and analyzed with GeneMapper@ID-X software. The Population genetics parameters were evaluated with Power States v 1.2 software. In addition, The effect of system about trace and mixture sample was observed. Results: The twenty-three autosomal STR loci were of high polymorphism in Guangdong Han population.TDP was 1-2.30×10-28 ,TPE was 0.999 999 999. DYS391 and DYS570 DYS576 loci GD value was 0.481, 0.791and 0.751, respectively. Three Y - STR in 172 unrelated individuals male 58 kinds of haploid type was detected, haplotype polymorphism of 0.337. The trace and mixture samples STR detection rate is 93.33% and 96.67%. Conclusion: PowerPlex? Fusion 6C is a high genetic polymorphism system, which can be used for kinship analysis, identification of the individual, and database construction.

Key words: forensic science , Guangdong Han population, allele frequency, autosomal STR, Y-STR