Abstract: Polyphenols was extracted from gingers by ultrasonic extraction method.The antioxidant effect was studied by color reaction of ferrous tartrate with the polyphenol extract.The optimized extraction conditions were obtained by orthogonal experiments. The results showed that the optimum extraction conditions were as follows:the extraction temperature of 60℃,the ratio of material to liquid of 1︰15(g/mL),the ethnol concentration of 70% and the extraction time of 45 min.The amount of polyphenols extracted from ginger was 18.50 mg/g. Antibacterial test showed that ginger polyphenols has certain inhibition effect to E. coli.