Abstract: The single nucleotide polymorphism (SNP) of growth hormone gene was investigated in six different pig breeds，including four minipig breeds which were Wuzhishan pigs，Bama pigs，Xiang pigs and Tibet pigs，and other two breeds which were Dalan pigs and Landrace pigs. Three pairs of primers for promoter region of GH gene were designed on the basis of database of pig genomic sequence and the SNPs were detected by PCR-SSCP method. The results indicated that three mutations were in the 5′flanking region. The analysis results showed that the frequencies of allele A and D in four minipig breeds were higher than that in other breeds at locus of 5′flanking region (P<0.05). According to the above results， difference of body size may have relationship with these SNPs of 5′flanking region and amino acid mutation of the leading peptide of GH in these pig breeds.