Abstract: OBJECTIVE To study the effects of Radix Saposhnikoviae on the metabolism of calycosin-7-O-β-D-glucoside as the main active component in Radix Astragali in intestinal flora of rats， exploring the scientific connotation of compatible application of Radix Astragali-Radix Saposhnikovia from the perspective of metabolism. METHODS The concentrations of calycosin-7-O-β-D-glucoside and calycosin between Radix Astragali group and Radix Astragali-Radix Saposhnikoviae group， as well as calycosin-7-O-β-D-glucoside monomer group and calycosin-7-O-β-D-glucoside-Radix Saposhnikoviae group at different time points were compared， respectively， by intestinal flora experiments. RESULTS Compared to Radix Astragali group， the concentration of calycosin-7-O-β-D-glucoside significantly increased in Radix Astragali-Radix Saposhnikoviae group (P<0.01)， while the concentration of calycosin significantly decreased (P<0.01) at different time points. Compared to monomer group， the concentration of calycosin-7-O-β-D-glucoside was significantly higher than that in calycosin-7-O-β-D-glucoside-Radix Saposhnikoviae group (P<0.01) and the concentration of calycosin was significantly lower (P<0.01). CONCLUSION Radix Saposhnikoviae can inhibit the transformation from calycosin-7-O-β-D-glucoside to calycosin and slow its metabolism.