Astragalus saponin I (Asl, isolated fromastragalus membransceus Bge) had an ana-lgesic action by HAC-writhing test andhot plate method in mice. The medianan algeslc dose (ED50) was 47. 81 ±3. 38mg/kg iv with HAc-writhing test and 25. 4±1. 5mg/kg iv with hot plate method. Asl50mg/kg iv prolonged the anaesthetic ef-fect of sodium thiopental in mice. It inh-ibi ted the tone of isolated ileum of gui-nea pig (at the concentration of 0. 4-40meg/mi) .