The differences in the composition and content of flavonoids in Sophorae Flos Immaturus extracted by heating reflux and ultrasonic-assisted extraction were investigated.The qualitative and quantitative analyses of four flavonoids,including rutin,nicotiflorin,narcissoside and quercetin,were established using high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS).The heating reflux and ultrasonic-assisted extraction conditions were optimized based on the absolute contents of the four flavonoid compounds,and optimized extraction methods were developed.Principal component analysis and partial least squares-discriminant analysis were employed to compare the composition differences between the extracts obtained by the two extraction methods.The results showed that the four flavonoid compounds had different optimal extraction conditions,their total contents in the heating reflux and ultrasonic-assisted extracts were 245.82 mg/g and 303.34 mg/g,respectively.Significant difference was observed between the extracts of the two extraction methods in 23 components,of which nine differential compounds,were identified.This study clarified the differences in flavonoid composition extracted from Sophorae Flos Immaturus by heating reflux and ultrasonic-assisted extraction methods,providing valuable references for the efficient extraction of flavonoid compounds in Sophorae Flos Immaturus.