Objective: To study the chem. constituents (total flavonoids) of Semen Astragali Complanati.Methods: Chem. constituents were isolated from Semen Astragali Complanati by chromatog. methods, and their structures were elucidated by anal. of spectral data and physicochem. properties.Results: Eleven compounds were isolated and identified as cannabiscitrin (I), myricetin-3-O-β-D-glucopyranoside (II), quercetin-3-O-β-D-glucopyranoside (isoquercitrin) (III), quercetin-3-O-α-L-arabinoside (IV), calycosin-7-O-β-D-glucopyranoside (V), ononin (VI), laricitrin-3-O-β-D-glucopyranoside (VII), kaempferol-3-O-β-D-glucoside (VIII), calycosin (IX), complanatuside A (X), and rhamnocitrin-3-O-β-D-glucoside (XI).Conclusion: Compound VII was isolated from Semen Astragali Complanati for the first time.