Abstract: Flavonoids was extracted from jackfruit peel by ultrasonic assisted solvent extraction method and the effects of different extraction solvents and extraction methods on the extraction rate of flavonoids were studied.At the same time,the effect of solvent concentration,ratio of material to liquid and extraction time on the yield of flavonoids from jackfruit peel were studied and the extraction process was optimized by the response surface experiment design.Results showed that the optimum extraction conditions were 61% solvent concentration,solid-liquid ratio 1 ∶ 25,extraction time 24 min,extraction temperature of 45 ℃,ultrasonic power 300 W.Under these conditions,the extraction rate of flavonoids could reach up to 6.92% with a significant antioxidant ability. Moreover,the scavenging capacity of DPPH and OH free radical value( IC50) was ordered as follows: crude extract > VC solution and crude extract > BHT solution,as well as the reduction ability better than the VCsolution.