Abstract: Polymerase chain reaction (PCR) and direct nucleotide sequencing were used to analyze the mitochondrial D-loop gene of 199 Zhejiang patients with T2DM and 102 controls and the relationship between D-Loop gene variations and the main clinical symptoms. The mitochondrial D-Loop gene was a hypervariable area and np73A-G, np263A-G, np16223C-T, and np16519T-C were four high variations, and 29 unreported new variations were found. np193A-G, np234A-G, and np16108C-T were related to diabetes mellitus with family history. These results showed that there are vari-ous forms of polymorphism in mitochondrial DNA D-Loop gene in a Zhejiang population, some of which are related to diabetes mellitus.