The genetic diversity of eight domestic pigs was analyzed using a hypervariable fragment in the mitochondrial (mt) DNA control region; a portion of the hypervariable control region (515 bp) was sequenced from 153 samples. Haplotype diversity and nucleotide diversity in Yushan black pig populations were significantly higher than other populations (p < 0.01). A neighbor-joining tree was constructed from domestic pig mtDNA and five wild pigs. The results indicate that there are only small differences among individual pigs from different regions. Networks of the domestic pigs were constructed to better visualize the relationships between sequences. Each core haplotype was surrounded by a star-like pattern, consistent with recent population expansion.