Objective To investigate the effect of ambient temperature on body mass, thermogenic activity and uncoupling protein-1(UCP1) content of brown adipose tissue (BAT) in tree shrews (Tupaia belangeri), and to provide theoretical basis for establishing tree shrews model of obesity. Methods Forty healthy adult tree shrews with similar body mass were uesd in our experiment. The tree shrews were divided into five groups (n=8):control group (0 d), the animals were maintained under 25±1℃ and 12L:12D (light:dark, lights on 08:00) photoperiod; and the animals were maintained under 5±1℃ and 12L:12D photoperiod for 7 d, 14 d, 21 d and 28 d groups, respectively. At the end of experiment, the changes of body mass, nonshivering thermogenesis (NST), BAT mass and uncoupling protein 1(UCP1) content were determined. Results Compared with the control group (0 d), the body mass, NST, BAT mass and UCP1 content of the cold acclimation groups were improved significantly, the BAT color also obviously deepened, and after cold acclimation for 28 d, the body mass, NST, BAT mass and UCP1 content were increased by 26.32%, 20.65, 53.85% and 43%, respectively. Apparently, the UCP1 content was significantly positively correlated with BAT mass and NST. Conclusions BAT proliferation may be induced and UCP1 expression upregulated by cold acclimation in Tupaia belangeri, therefore, enhancing the thermogenic activity of brown adipose tissue to increase energy expenditure. We would speculate that BAT might be used as a target organ for treatment of obesity by energetic approach in the future.