Abstract: The present paper dealt with the feed containt different proteins influences the nitrogen balance in tree shrews.For a period of 15-days,five groups of tree shrews (total of 30) were fed formula feeds containing 10%,15%,20%,25%,and 30% crude protein,respectively.The mean daily deposited nitrogen amount of five group animals was 64.7±18.2 mg,157.4±16.6 mg,276.4±39.4 mg,485.2±73.1 mg,and 494.1±83.9 mg,respectively.The mean nitrogen deposited rate of five group animals was 14.9±4.7%,28.8±6.3%,35.2±6.9%,50.6±1.9%,and 40.4±7.4%,separately.According to statistical analysis,there are extremely remarkable differences between five group animals in the mean daily deposited nitrogen amount and the mean nitrogen deposited rate (P<0.01).The above results indicate that the formula feed containing 25% crude protein is advantageous to the health of growing tree shrews and saving on feeding cost under our feeding condition,or more accurately,it is appropriate that a growing tree shrews ingests 52.0-62.0 g crude protein/kg body weight per day.