The objective of this study was to investigate the polymorphism of seven Y-specific STR loci in Shui ethnic population of Guizhou, China, and to obtain the polymorphism information in this minority. One trinucleotide STR locus and six tetranucleotide STR loci were simultaneously amplified with fluorescently labeled primers, and genotypes were determined with ABI PRISM 377 DNA Sequencer. Allele frequencies, genetic diversity and haplotype diversity were calculated. Among 94 unrelated males, 6, 4, 6, 2, 3, 5, 4 alleles were observed in loci DYS19, DYS389 I, DYS389 II, DYS390, DYS391, DYS392 and DYS393, respectively. Altogether, 27 haplotypes were identified for the seven Y-STR loci. The genetic diversity values for each locus ranged from 0.124 (DYS389 I) to 0.630 (DYS19). The haplotype diversity value was 0.868. High haplotype diversities were found in Shui population of Guizhou. The study suggests that these seven Y-STR loci are valuable Y-specific markers for establishing a Y-STR database, understanding ethical origin and migrations and for personal identification.