Abstract: Bahan F2 sheep at the ages of 5 months were compared with small- tail lambs and Sunit lambs of the same ages in terms of slaughter performance.Besides longissimus dorsi of 5 months Sunite sheep were compared with biceps femoris and arm triceps in terms of color parameters,tenderness,p H,rate of meat loss and fatty acids content.The results showed slaughter performance of Bahan F2 sheep was better than small- tail lambs and Sunit lambs,Dressing percentage were significantly higher than those of Sunit lamb,lean meat yield were significantly higher than those of small- tail lambs( p < 0.05).In addition,longissimus dorsi of bahan F2 sheep in terms of color parameters,tenderness,p H,rate of meat loss and fatty acids content were better than biceps femoris and arm triceps and unsaturated fatty acid content in longissimus dorsi was higher than biceps femoris and arm triceps.As the standard evaluation of mutton nutrition value,the longissimus dorsi of bahan F2 was best.