Abstract:The flavonoids in konjac were extracted by methanol-ultrasound-assisted extraction.Combined with Box-Benhnken，the experiments were designed to determine the influenced order of various factors，methanol concentration＞ultrasonic temperature＞solid-liquid ratio＞ultrasonic time.The mathematical model was established to determine the optimal extraction conditions of flavonoids by multiple regression analysis using Design-Expert8.0software.Theoptimumextractionconditionswereultrasonictime35min，ultrasonictemperature 40℃，methanol concentration 88%，solid-liquid ratio 1∶32（g/mL）.Under such condition，the extracted yield of flavonoids was 1.73 mg/g.It was concluded that the contents of flavonoids in red konjac flour and skin were 1.73 mg/g and 2.40 mg/g，and in Jinzhu No.2 flowr and skin were 1.60 mg/g and 2.21 mg/g under optimal process conditions，respectively.Gas chromatography-mass spectrometry（GC-MS）was used to identify the chemical components of the volatile oil among Jinzhu NO.2 and red konjac.Twenty-eight compositions of volatile oil were identified after being separated by ether.The relative contents of eleven common components were more than 85%.