A total of one hundred and twenty 1-day-old apparently healthy Japanese quail were selected and randomly divided into 4 groups. Treatments were designed with four levels of crude protein (22.17, 24.2, 26.2 and 28%) respectively to study the effects of dietary crude protein level on growth performance, carcass characteristics , intestinal microflora, hematological parameters and some biochemical changes of growing Japanese quail. Results showed that growth performances parameters significantly improved as dietary crude protein level increased .The results indicated that dietary protein level beyond 24% has no beneficial effect on growth. Carcass traits results revealed that dressing percentage, breast muscles and leg muscles were increased significantly as crude protein level increased in the diet but weights of liver, heart gizzard and abdominal fat percentage were decreased significantly . Intestinal microflora count revealed that total aerobic bacteria, Coliform bacteria, Lactic acid bacterium and Escherichia coli increased significantly as crude protein level increased. Hematological examinations results demonstrated that hemoglobin concentration, red blood cells count, total leucocytic count , monocytes and lymphocytes were increased significantly as crude protein increased but basophils, eosinophils and heterophils were decreased significantly. Serum analysis showed that total protein, albumin and globulin in serum increased significantly as crude protein increased. It could be concluded that dietary level of 24% crude protein is recommended for growth performances and economic efficiency of growing Japanese quail because of increased dietary protein level beyond 24% % has no beneficial effect on growth