Abstract: The essence of life is the interaction of structure and energy.However,in modern medicine,little is known about the defects in energy metabolism in the disease.Energy is mainly produced in mitochondrion,which generates ATP that can be used directly by the oxidation of respiratory chain and generates harmful reactive oxygen species (ROS) at the same time.From the perspective of genes,there are hundreds of copies of mitochondrial DNA in each cell.And the mitochondrial DNA encoded proteins form part of the respiratory chain,which is essential for energy production.Mitochondrial dysfunction is associated with the occurrence and development of many diseases.Different tissues differ in the number of mitochondria due to different energy requirements.When the energy which produced by mitochondria is unable to meet the needs of the body,disease will occur.For example,type 2 diabetes mellitus (T2DM),high blood pressure,deafness,etc.At present,the incidence of T2DM is increasing by years,and previous research has shown that it is related to the occurrence and development of mitochondria.Therefore,this paper gives a general review of research on the risk of T2DM from the change of the structure and function of mitochondria,energy metabolism,mitochondrial DNA variants and haplogroups.