Abstract: This experiment was conducted to investigate the effects of dietary crude protein（CP）level on growth performance, carcass traits, body protein deposition and blood biochemical indices of Ningdu yellow chickens in order to determine CP requirements of Ning-du yellow chickens at different growth phases. A single factor complete randomized trial design was adopted. In three separate phases, 600, 480 and 336 female Ning-du yellow chickens with similar body weight at 1, 29 and 57 days of age were randomly assigned into four groups with six replicates of 25, 20 and 14 each, respectively.The CP levels were 17.0%, 18.5%, 20.0%, 21.5% at 1 to 28 days of age; 15.5%, 17.0%, 18.5%, 20.0%at 29 to 56 days of age; and 14.0%, 15.5%, 17.0%, 18.5% at 57 to 105 days of age, respectively. The results showed that at 1 to 28 days of age, the ratio of feed to gain（F/G） of 20.0% and 21.5% groups were significantly lower than that of 17.0% group（P＜0.05）; body protein content and daily protein deposition in 20.0% group were extremely higher than those in 17.0% and 18.5% CP groups（P＜0.01）,daily protein deposition in 20.0% group was higher than that in other groups（P＜0.05）, the body CP deposition rate in 17.0% and 20.0% groups were extremely higher than that in 21.5% group（P＜0.01）. At29 to 56 days of age, the final weight and the average daily gain（ADG） in 17.0% group was significantly higher than those in 20.0% group（P＜0.05）, the F/G of 17.0% group was significantly lower than that of18.5% and 20.0% groups（P＜0.05）; the body CP deposition rate in 18.5% and 20.0% groups were extremely higher than that in 15.5% and 17.0% groups（P＜0.01）; the serum TC in 17.0% CP group was significantly lower than that in other groups（P＜0.05）; the serum TG in 17.0% and 18.5% groups were significantly lower than that in 20.0% group（P＜0.05）, serum GLU in 15.5%, 17.0% and 18.5% groups were extremely lower than that in 20.0% group（P＜0.01）; the serum TP in 17.0% group was extremely higher than that in 15.5% and 20.0% groups（P＜0.01）. At 57 to 105 days of age, final weight and ADG in15.5% group were significantly higher than those in 17.0% and 18.5% groups（P＜0.05）, the F/G of14.0% and 15.5% groups were significantly lower than that of 18.5% groups（P＜0.05）; body protein content in 15.5% CP group was higher than that in 14.0% and 18.5% CP groups（P＜0.05）, and daily protein deposition in 15.5% CP group was extremely higher than that in 18.5% CP group（P＜0.01）; with dietary CP level increasing, the dressing percentage at 105 days of age showed a decreasing trend（P＜0.05）; compared with 14.0% and 17.0% groups, eviscerated yield percentage in 18.5% group was significantly increased（P＜0.05）, abdominal fat percentage was significantly decreased（P＜0.05）. Based on the results, 20.0%, 17.0% and 15.5% dietary CP levels were recommended for Ningdu chickens at 1 to 28 days of age, 29 to 56 days of age and 57 to 105 days of age, respectively.