Objective:To establish the method of quantitative analysis of multi-components by single-marker (QAMS) in the determination of five flavonoids in the flower of Salix caprea L. MethodsUsing rutin as the reference substance, the relative correction factors of luteolin-7-O-β-D-pyranoside, apigenin-7-O-β-D-pyranoside, luteolin and apigenin were calculated by high performance liquid chromatography (HPLC). Related influencing factors were investigated and the relative correction factors were determined. The content of the other four components was calculated directly using the content of rutin and the relative correction factors to establish the QAMS method with rutin as the reference substance. The results were compared with those obtained by external standard method.  Results:The relative correction factors were fluteolin-7-O-β-D- pyranoside / rutin =1.49 (RSD=1.84%), fapigenin-7-O-β-glucopyranoside / rutin =2.26 (RSD=2.26%), fluteolin / rutin =2.63 (RSD=1.01%) and fapigenin / rutin =2.86 (RSD=1.55%), with good repeatability. There were no significant differences between the values obtained with the QAMS method and those obtained with external standard method, and the correction factor obtained was reliable.  Conclusion:It is feasible and accurate to determine the content of five flavonoids in flower of Salix caprea L. by the QAMS method, which can be used for quality evaluation of the flower.