Abstract: In order to explore the nutritional composition difference between red beef and marble beef produced by Sanjiang cattle high quality beef production technology system, 11 healthy Sanjiang cattle aged four to five months were randomly selected from the same resource group in Sanjiang cattle breeding area, Sanjiang Township, Wenchuan County, including seven bulls and four cows. Then, three cattle（two bulls and one cow） were randomly selected and fed to 24 months of age according to Sanjiang Red Beef Production Technical Specification before slaughter. The other eight cattle（five bulls and three cow） were fed to 36 months of age according to Sanjiang Marble Beef Production Technical specification before slaughter. The content of moisture, protein, fat, cholesterol, ash, vitamin A, vitamin C, vitamin B₁, vitamin B₂, vitamin E, mineral elements（Ca、P、Mg、Fe、Zn、Cu、Mn、Se、K、Na） and amino acids in Sanjiang red beef and marble beef were determined, and the contents of total amino acids（TAA）, flavor amino acids（FAA）, essential amino acids（EAA）, and non-essential amino acids（NEAA） were calculated, the differences between two kinds of beef were compared and analyzed. The results showed that the Sanjiang beef was rich in various vitamins, minerals and flavor amino acids. The moisture content in red beef were 67.47%, which were significantly higher than marble beef with 61.39%（P＜0.05）. The contents of vitamin B₁ and Zn in red beef were 0.05 mg/kg and 34.73 mg/kg, respectively, which were significantly higher than those in marble beef（0.03 mg/kg and 27.09 mg/kg, P＜0.01）. The Fe and Se contents of marble beef of Sanjiang cattle were 23.66 mg/kg and 0.09 mg/kg, respectively, which were significantly higher than those of red beef（18.57, 0.03 mg/kg, P＜0.01）. There were no significant differences in protein, fat, cholesterol, ash, vitamin B₂ and vitamin E contents between the two kinds of beef（P＞0.05）. There were no significant differences in TAA and EAA contents between the two kinds of beef, and the histidine content of marble beef was extremely significantly higher than that of red beef（P＜0.01）, and the cystine content of marble beef was significantly higher than that of red beef（P＜0.05）. The EAA/TAA and EAA/NEAA values of marble beef were higher than red beef（P＞0.05）. Vitamin A was not detected in either beef. It indicated that Sanjiang marble beef and red beef were both high-quality beef with high nutritional value. The red beef contained less fat and more vitamin B₁ and Zn, while marble beef had better amino acid composition and higher Fe and Se content.