Abstract: The aim of the present study was to investigate the effect of different protein dietaries on the digestibility of nutrients and serum biochemical indicators in male sika deer.Fourteen one-year old male sika deer were randomly allocated into four groups and fed four different diets with crude protein levels of 10.27%,14.26%,15.61% and 18.60%,respectively.Feeding trial and digestion trial were performed.Dry matter intake,weight,nutrient intake and digestibility,crude protein intake and digestibility,feed conservation ratio and serum biochemical indicators were determined.The results showed that the optimum protein level in diet of one-year old male sika deer was 18.60%.