Abstract: 【Objective】To clarify the phenotypic differences in growth,carcass traits and meat quality indexes between Tibetan and Duzang pigs(F₁ generation crossed between Duroc male and Tibetan pig female)and to analyze the differences in the expression of fat depositing-related genes in longissimus dorsi muscle,so as to provide a reference for the utilization of Tibetan pig germplasm resources and the study of pig fat deposition.【Method】Tibetan and Duzang pigs were used as the research objects,and their growth traits such as body length,height,chest circumference,slaughter rate,back fat thickness,eye muscle area and meat quality indicators such as pH,meat colour,cooking loss and intramuscular fat content were measured respectively.The expressions of fat deposition-related genes in the longissimus dorsi of the two pigs were also detected by real-time quantitative PCR.【Result】The left carcass weight,right carcass weight,preslaughter weight,carcass length,body length,body height,tube circumference,and chest circumference of Duzang pigs were higher than those of Tibetan pigs.The difference was significant(P<0.05,the same below),and the eye muscle area(33.00±3.84 cm²)was also considerably larger than that of Tibetan pig(16.83±1.81 cm²),the thickness of back fat(13.15±2.48 mm)was significantly lower than that of Tibetan pigs(22.83±2.80 mm).At the same time,there was no significant difference in skin thickness,abdominal circumference and slaughter rate between Tibetan pigs and Duzang pigs(P>0.05,the same below).The p H-24 h,cooked meat rate,shearing force and water content of Duzang pig muscle were significantly higher than those of Tibetan pig muscle.The colour a-24 h value(10.30±1.06)and intramuscular fat content(2.48±1.44)%of Duzang pigs were significantly lower than those of Tibetan pigs.Except for GHR,the relative expression of ADIPOQ and FASN were significantly lower in Duzang pigs than in Tibetan pigs,and the relative expression of IGF1,TNFa and Leptin were extremely lower than in Tibetan pigs(P<0.01).The results of correlation analysis showed that the relative expression of GHR was significantly positively correlated with the intramuscular fat content in Duzang pigs.Furthermore,the relative expression of FASN was significantly positively correlated with the intramuscular fat content in Tibetan pigs.In addition,the relative expression of IGF1 was significantly negatively correlated with the back fat of Tibetan pigs.【Conclusion】The meat quality traits of Duzang pigs are similar to those of Tibetan pigs,but Duzang pigs have better growth performance,indicating that Duzang pigs obtained by crossing Duroc male and Tibetan pig female have better production efficiency.The difference in intramuscular fat content between Tibetan and Duzang pigs is related to the difference in the expression of fat deposition-related genes.That is,a variety of fat deposition-related genes regulate the intramuscular fat content of pigs.