This study was carried out to evaluate the value of three X-STR loci (DXS6803, DXS981and DXS6809) in forensic application and thereby investigate their polymorphism. The primer for each locus was labeled with fluorochrome 6-FAM. A fluorescent multiplex PCR for simultaneously amplifying three X-STR loci was set up. The PCR products that were obtained were analyzed using capillary electrophoresis and ABI PRISM 3100 Genetic Analyzer, with GENESCAN Analysis Software. When 340 male and 195 female individuals of Han population in China were tested, 13, 12, and 11 alleles were observed for DXS6803, DXS981 and DXS6809, respectively. One hundred and eighty three haplotypes were detected in the male individuals. The haplotype diversity reached 0.9926. The results show that the three loci of the multiplex system provide significant information on polymorphism for forensic identification and paternity testing, particularly for complicated paternity deficient cases.