This study was looking for the effects of energy levels and growth performance on physical characteristics of Iranian lambs’ meat. Forty-eight male lambs (initial BW 31.6kg) and 5-month age were assigned to a completely randomized design with factorial method includes fattening periods (12weeks and 15weeks) and levels of metabolism energy (ME) (2.36 and 2.62 ME M cal/kg DM intake). Diets were iso-nitrogenous (14.1 percent crud protein on DM). The rations were mixed and have been fed ad-libltum. The lambs were weaned at 90±5 days of age and divided randomly in two fattening periods groups includes 12weeks and 15weeks (2×24 lambs) and each fattening periods split in two energy levels (2×12). At the end of each fattening period, half of the lambs (24 lambs) were randomly selected and after 18h fasted slaughtered. After trimming and skinning, all the abdominal and interior organs were removed and weighed. The warm carcasses were chilled at 3±2ºc for 24 h and weighed, after that their carcass cuts composition was measured. All data were analysed as a completely randomized design with factorial experiment using the GLM procedure of SAS (2010). The average of final, metabolic and hot carcass weight for 12 weeks fattening were 48.1, 18.2 and 25.5 kg and for 15 weeks fattening were 50.9, 19.1 and 27.5 kg (p< 0.05). Among fattening period (12weeks and 15weeks) and different levels of metabolism energy for final, metabolic and carcass weight had significant (p< 0.05). The total mean of dressing percentage between fattening periods and different levels of energy was not significant. The mean of total carcass meat, bone, and subcutaneous fat and fat-tail percent for 12weeks fattening were 46.7, 11.7, 15.3 and 22.5 percent and 15weeks fattening were 45.9, 11.7, 16.1 and 23.6 percent respectively. But between fattening period and different levels of energy for carcass meat, bone, subcutaneous fat and fat-tail percent were not significant. However, the 12weeks fattening period and 2.36 M Cal ME/kg DM of metabolism energy positive effects on some carcass characteristics, because lower subcutaneous fat and fat-tail percent and carcass composition were not significant.