RESUMEN
<p><b>OBJECTIVE</b>To investigate the polymorphic distribution of short tandem repeat (STR) sequences D21S1433, D21S1442, D21S1444, D21S2051 in Guangdong Han nationality in China.</p><p><b>METHODS</b>Using quantitative fluorescens PCR technology, the authors analyzed 200 unrelated samples to acknowledge the allele frequency, heterozygosity and other genetic information.</p><p><b>RESULTS</b>D21S1433, D21S1442, D21S1444, D21S2051 were tested in 200 samples, which were tested to be statistical according to Hardy-Weinberg equilibrium (P> 0.05), 9, 10, 9 and 5 alleles were detected separately in each STRs. The heterozygosity of each STR was 0.818, 0.820, 0.770, and 0.261. The polymorphic information content > 0.7 in D21S1433, D21S1442, D21S1444, while D21S2051 owned only 0.247 polymorphic information.</p><p><b>CONCLUSION</b>D21S1433, D21S1442, D21S1444 are found to have high heterozygosity and polymorphic information content, and they could provide useful markers for genetic purposes, while D21S2051 is not informative in Guangdong Han nationality in China.</p>