Abstract: To research the different methods on extracting flavonoid from water chestnut peel，the research extracted flavonoid from water chestnut peel under different conditions，and choose the suitable conditions with orthogonal test. The results showed with ultrasonic heating method ，it extracted the most flavones，the suitable conditions in this method were heating time 50 min，50% ethanol，60 ℃，solid-liquid ratio of 1∶30，under the conditions，the yield of flavones was 2. 438% ；the secondary was microwave heating method，the suitable conditions were 420 W，solid- liquid ratio of 1∶30，50% ethanol，heating time 5 min，under the conditions，the yield of flavones was 2. 455%；with the bathing heating method，it extracted the least flavones，the suitable conditions were 60 ℃，60% ethanol，solidliquid ratio of 1∶30，heating time 4 h，under the conditions，the yield was 1. 618%. The three methods each has its advantage and disadvantage，can be used in different situation.

Key words: water chestnut peel, flavones, water bath heating, microwave heating, ultrasonic heating