Abstract: In order to assess the meat quality of different breeds of fattening Tibetan sheep after slaughtering,a group of 3-year-old stud rams belonging to four Tibetan sheep breeds,including Awang sheep,Gamba sheep,Pengbo semi-fine wool sheep and Amdo sheep were selected in this study.Under the same feeding and management conditions,the rams were fattened in a manner of ′semi-confinedness + fresh grass + straw + formula concentrate' for a period of three months.After slaughtering,the longissimus dorsi muscle of 1 kg was sampled from each ram individual and was used to perform meat quality analysis.The highest sensory score,the best acceptability,the highest brightness value (L^* value was 43.09),and the best gloss were observed in the meat of Gamba sheep.For the meat of this breed,the shearing force was 2 960 g,the hardness was 1 140 g,the cohesive force was 0.419 kPa,and the elastic force was 0.25 N,indicating the best texture quality;the meat water-holding capacity was 34.3%,the cooking loss rate was 30.3%,suggesting the features of tender and soft.In addition,the Gamba sheep meat had the highest contents of total fatty acids,saturated fatty acids and unsaturated fatty acids,which were 5.96,2.89 and 3.08 g/100 g,respectively.Except for Awang sheep,the ratio of essential amino acids to total amino acids and the ratio of essential amino acids to non-essential amino acids in meat of the other three breeds of Tibetan sheep exceeded or approached to the standards set by the Food and Agriculture Organization of UN and the World Health Organization.The highest values of total amount of amino acids and essential amino acids were observed in Amdo sheep meat,which were 22.8 and 9.89 g/100 g dry matter,respectively.The combined data suggest that Gamba sheep meat has the highest sensory score as well as the best food quality and processing quality,and Ando sheep meat has the highest nutritional value.