Allele frequencies of 11 X-chromosome STRs loci, namely DXS7133, DXS6799, DXS8378, DXS7423, DXS6804, HPRTB, DXS7424, DXS7132, DXS6789, DXS101 and DXS1214, were determined from healthy unrelated individuals (110 female and 94 males) of Han ethnic group from Northwest China.