In the study,the core region of porcine AZ1 gene promoter was identified through the Dual-luciferase Reporter Assay System.SNPs and haplotypes were analyzed in Lantang and Landrace pig populations,and the transcriptional activities of different haplotypes were measured.The results showed that the region of ??453 /+79 nt was the core region of the promoter.Eight SNPs were found in the two populations,and they were ??713 T>C,??584 A>C,??476 G>A,??365 T>C,??348 C>T,??294 G>C,??288 T>G,and ??234 T>C.Richer SNPs were found in the Lantang pigs.In the Landrace population,GG and GT genotypes were found at ??288 locus,and no heterzygotes were detected in the other seven loci.The frequencies of predominant haplotypes of LTH1 (TAGCCGTC) and LTH2 are 0.526 and 0.166 respectively in Lantang population,and the Landrace-H haplotype (TAGTCGGT) was predominant in the Landrace population.The activity of LTH1 was stronger than that of LTH2 and Landrace-H.The SNPs of ??234 T>C,??365 T>C and ??288 T>G might be the causative mutations that change the different activities of the haplotypes.