A 506 bp segment of the porcine growth hormone gene encompassing base 206 of the first intro through base 711 of the third exon was amplified by PCR. Two polymorphic restriction sites for ApaⅠ, MspⅠ were identified at 295-300, 563-566, respectively. DNA was from five breeds, which were Pietrain, Duroc, Landrace, Jiangquhai, Meishan. The genotype and allele frequencies in each polymorphic restriction sites were calculated, and the difference in genotype and allele frequencies in five breeds were tested by χ 2 test. The result showed that the difference in genotype and allele frequencies at MspⅠ and ApaⅠ polymorphic restriction sites in five breeds is significant ( P 0 01). The highest allele frequencies in MspⅠ polymorphic restriction sites was G 1 in Pietrain. But the G 2 allele frequencies is higher in others breeds. The allele frequencies in ApaⅠ polymorphic restriction sites for G 4 was high in five breeds.