Abstract: The field experiments were carried out in chicken farm and chicken raising households to evaluated the effect of low crude protein diet on the production performance and culture benefit of long days three-yellow chicken. A total of 1 600 three- yellow chicken were selected in a chicken farm and randomly divided into four groups （control, experimental group 1, 2 and 3 ）. There were two replications for each groupand 200 chickens in each replication. The chicks （age of 1-35 d） and adult chickens （from age of 76 d to sale） of control and experimental groups fed with routine diet, the middle age chickens （age of 36-75 d） of control group fed with diet containing 17% crude protein and those of experimental group 1, 2 and 3 fed with low crude protein diet containing 14%, 12% and 10% crude protein, respectively. The digestible essential amino acid content of diet for each group was same. A total of eight chicken raising households were selected and randomly divided into four groups （control group I and II, experimental group I and lI ）. There were two chicken raising households in each group and 8 000 chickens in each chicken raising household. The chicks （age of 1-35 d） and adult chickens （from age of 76 d to sale） of control and experimental groups fed with routine diet, the middle age chickens （age of 36-75 d） of control groups fed with diet containing 17% crude protein and those of experimental groups fed with low crude protein diet containing 14% crude protein. The digestible essential amino acid content of diet for each group was same. The ingestion behavior type of control I group and experimental group I were restricted feeding and control U group and experimental group II were ad libitum feeding. During tile two field experiments, the daily feed consumption for each group was recorded. In the end of the experiments, the sale rate, average individual weight, ratio of feed to gain, defective chickens rate and average individual benefit of each group were calculated and statistically analyzed. The results of the chicken farm experiment showed that there were no significant differences in sale rate, ratio of feed to gain and defective chickens rate among the groups （P〉0.05）. However, the average individual weight of experimental group 3 was significantly lower than that of other experimental groups （/~0.05）, and the average individual benefit of experimental group 1 was significantly higher than that of control group and other experimental groups. The results of the chicken farm experiment showed that the defective chickens rate of experimental group I was significantly higher than that of control I group and experimental group 1T. It was indicated that feeding with low crude protein diet containing 14% crude protein in middle age chickens could increase the average individual benefit of three-yellow chicken, and the ingestion behavior type of ad libitum feeding was preferred.