A method for sex determination of pigs was examined using polymerase chain reaction(PCR). Sex determining region Y(SRY) gene encoded on Y chromosome plays a key role for primary male development. Zinc finger X-Y(ZFX-ZFY) gene, one of the X-V homology gene group was found on the X and Y chromosomes, respectively, We tested for molecular sexing by amplification patterns of SRY and ZF genes. Genomic DNAs from various resources including porcine hairs and semen collected from domestic pig breeds and native pigs was used for PCR assay of each gene. The amplified products for porcine SRY gene were yielded only in males but not in females. On the other hand, two differential patterns were observed in amplification of ZF gene reflecting the chromosomal dimorphism by a length polymorphism between X and Y chromosomes. Of both, a common band was detected in all individuals tested so that this band might be amplified from ZFX gene as a PCR template, but another is specific for males indicated that from ZFY. The result of PCR assay provides identical information to that from investigation of phenotypic genders of the pigs tested. We suggest that this PCR strategy to determine porcine sexes using comparison of the amplification patterns of the SRY gene specific for Y chromosome and the dimorphic ZF gene between X and Y chromosomes may be a rapid and precise method for discrimination of two sexes and applied to DNA analysis of small samples such as embryonic blastomere, semen, and hairs.