Abstract:The aim was to study the effect of different drying methods on the Citrus medica piece's antioxidant activity and the content of vitamin C，vitamin E and flavone.the results couold provide theoretical evident for industrial drying methods.Hot air drying，microwave drying and freeze drying were used in this study.The antioxidant activity and the content of vitamin C，vitamin E and flavone were measured and flavone extracted methods，water extraction and alcoholic extraction，were compared.The results showed that the total amount of flavonoid extracted by alcohol，which was（19.63±0.22）mg/100 g，was higher than that extracted by water.There were significant differences in the ability of removing superoxide anion among the three drying methods，the order was freeze drying（91.76）〉microwave drying（85.89%）〉hot air drying（84.79%）.The order of hydroxyl radical scavenging ability was freeze drying（88.39%）〉 hot air drying（78.40%）〉 microwave drying（77.12%）.The content of VC and VE that drying method was freeze drying was significant higher than that dried by hot air drying and microwave drying（p〈0.05）.The order of flavone content was freeze drying〉 hot air drying〉microwave drying.The conclusion freeze drying was better than hot air drying and microwave dry freeze drying could be drawn.