Rosa chinensis ‘An Ning Ba Jie'as the raw material,the extraction process of polyphenol and the antioxidant activity before and after purification were studied. The extraction temperature were identified as main factor that influence extraction efficiency.The optimum conditions for the ultrasonic extraction of polyphenols from rose were found to be with 70%ethanol at solid-to-liquid ratio 1 ∶ 25( g/m L) for 40 min with ultrasonic temperature 40 ℃ with extraction three times. Under these conditions,the extra...