In order to explore the adaptive mechanism that how does the white adipose tissue (WAT) of the tree shrews (Tupaia belangeri) reply to the change of the environmental temperature, the WAT of tree shrews, which came from three groups, the control group, cold acclimation group (28 day) and the rewarming group (28 day), were labeled by fluorescent labeled Ucp1 antibody and fluorescent labeled Cd137 antibody, and then were analyzed by the Flow cytometry to measure the white adipocytes which had Ucp1 and Cd137. As a result, the percentage of the white adipocytes which had Ucp1 and Cd137 in the cold acclimation group was higher than that in the control group significantly. Nevertheless, the percentage of the white adipocytes which had Ucp1 and Cd137 in the rewarming group was lower than that in the cold acclimation group significantly and returned to the percentage of that in the control group. The increase of the white adipocytes which had Ucp1 and Cd137 was observed in the tree shrews during cold acclimation. The browning of WAT in tree shrews could be induced during cold acclimation. The plasticity of WAT was reflected by that the percentage of the white adipocytes which had Ucp1 and Cd137 returned to what they once were after rewarming. Therefore, the plasticity regulation of WAT is also an important thermogenic mechanism for the tree shrews to adapt the changes of

ambient temperature.