Abstract: Twenty seven D`man lambs 6 months old (17.9; s.d = 3.1 kg) were used to study the effects of the concentrate crude protein (CP) content on growth performances, carcass and meat composition. Animals were randomly assigned to 3 groups of 9 lambs each and received individually oat hay ad-libitum and concentrates containing 130 (L), 180 (M) or 230 (H) g CP/kg DM. Hay intake averaged 49.7 g DM/kg W0.75/d and wasn`t affected by dietary CP content. Dry matter (DM), organic matter (OM), crude fiber (CF) and CP digestibilities were similar for all diets. Average daily gain (ADG) was higher (P<0.01) for H and M groups than for the L one (156.2 s.d = 13.5; 147.6 s.d = 20.1 and 120.3 s.d = 22.2 g/d respectively). Dietary CP had no significant effects on empty body weight (EBW), carcass weight, dressing percentage, external (skin, head, feet) and thoracic organs, carcass conformation and fat score. In all carcasses, fat was white and oily and lean was rose. Lambs of H group had relatively more muscle (P<0.05) and less fat (P<0.01) in the hind leg than those in the L treatment; the M group lambs had intermediate values. It was concluded that 110-120 g CP/kg DM would be the optimal level of protein content in diets of growing D`man lambs.