Abstract: In order to study the genetic diversity and systematic status of Sujiang pigs, the ear tissues of 47 Sujiang pigs were collected for genomic DNA extraction, and the complete mtDNA D-Loop region sequence was amplified by PCR and sequenced. The composition and content, sequence length, variation sites, haplotype number, haplotype diversity and nucleotide polymorphism indexes of 47 Sujiang-pig mtDNA D-Loop region sequences were analyzed to estimate the degree of sequence variation. The phylogenetic tree was constructed and the haplotype network relationship was analyzed. Finally, the haplotype phylogenetic tree of mtDNA D-Loop region of Sujiang pig was constructed using the mtDNA D-loop sequence of other 24 pig breeds. The results showed that the full-length sequence of Sujiang pig mtDNA D-Loop region was 1 194-1 274 bp, and the content of A, T, C, and G base were 32.9%, 24.8%, 26.5% and 15.8%, respectively. A total of three haplotypes and eight variation sites（all reduced information loci） were identified from 47 sequences. Haplotype diversity was 0.001 73; the nucleotide diversity was 0.499; the mean nucleic acid differences was 1.210, and the Tajima’s D value was-0.916 74（P＞0.10）, which was consistent with neutral mutations. The Sujiang pig herd had three branches, and it was speculated that it had three maternal origins, and it was closely related to the pig breeds in the south region of the Yangtze River. These results indicated that the genetic diversity of Sujiang pig population was relatively rich, with three maternal origins.