Abstract: ‘Zihong 1’apple is red-flesh apple，which belonged to F₁ of Xinjiang wild red-flesh apple[Malus sieversii f. neidzwetzkyana（Dieck）Langenf.] and‘Fuji’apple. Pulp of‘Zihong 1’apple was taken as material to determine the anthocyanin content，total phenolic content，flavonoid content and antioxidant activity. The results showed that they were 228.3 mg · kg^-1 FW，2 523 mg · kg^-1 FW，2 514 mg · kg^-1 FW and 13.39 μmol · g^-1，respectively. Nine anthocyanins were found in red pulp of‘Zihong 1’ apple assayed by UPLC-PAD-/MS/MS，of which four kinds of anthoyanins were detected as cyanidin 3-O-galactoside，cyanidin 3-O-glucoside，cyaniding 3-O-arabinoside and cyanidin 3-O-xyloside. cyanidin 3-O-galactoside was the main anthcyanin，which accounted for 73.3% of total anthocyanins. Structure of the other five anthocyanins couldn’t be determined temporarily. The stability of the anthocyanins was studied and found that the anthocyanins were more stable in aqueous solution which pH value was between 1 and 3，below 40 ℃. The high temperature accelerated degradation of the anthocyanins. The anthocyanins was sensitive to light and the residual amount was only 41.53%.

Key words: apple, red-flesh, anthocyanin, phenolic, antioxidant, anthocyanins stablity