The Tree Shrew(Tupaia belangeri) is a unique species of small mammals in the Oriental realm.In order to study their cold adaptive capacity in cold environment,the Ⅲ state and the Ⅳ state of mitochondrial respiration,the protein content of mitochondria of liver were measured under the condition of being cold exposure(5±1℃,12L:12D) during different times [0 d(control),7 d,14 d,21 d,28 d].Compared with the controls,the total protein,mitochondrial protein,and the Ⅲ state and the Ⅳ state of mitochondrial respiration of liver greatly increased with prolonged cold exposure(increased 39.9%,39.3%,84.9%,181.1%,respectively,after 28 d).The result indicates that the liver plays a key role of the adaptive thermogenesis during cold exposure in the T.belangeri.The physiological ecology evidence is also given to the island origin of T.belangeri.