Abstract:This study was conducted to analyze the flesh composition and flesh texture of Oncorhynchus mykiss,O. masou masou and their hybrid F1 (O.mykiss♀×O.masou masou ♂ ). The results showed that,(1) content of crude lipid of flesh was significant lower in crossbreed F1 than in its parents (P<0.05),moisture of flesh was lower in crossbreed F1 than in O.masou masou,but higher than in O.mykiss (P<0.05),while crude protein was lower than in O.mykiss,but higher than in O.masou masou (P<0.05);(2) the total amino acid,essential amino acid,non-essential amino acid and total delicious AA of flesh were higher in crossbreed F1 than in their parents,while semi-essential amino acid was higher in crossbreed F1 than in O.mykiss and lower than in O.masou masou;(3) the muscle nutritional quality evaluation results of crossbreed F1 and the parents show that the EAA index of crossbreed F1 was 77.77,which was approaching that of O.masou masou (79.19) and significant higher than that of O.mykiss (63.67);(4) there are significant difference between crossbreed F1 and the parents (P<0.05) in flesh color and tenderness,the measured value of crossbreed F1 was higher than that of O.mykiss and lower than that of O.masou masou. All of results showed that the flesh quality of O.masou masou is better than that of O.mykiss,the flesh quality of crossbreed F1,inheriting the characteristics of O.masou masou,was much better than that of O.mykiss.