Abstract:Extracellular microelectrode method and stereotaxic technique of brain were used to investigate the effects of Radix Salviae Miltiorrhizae on the discharges of visceral pain in the posterior nucleus of thalamus(po)in cats. Experiments showed that Radix Salviae Miltiorrhizae inhibited th dirschages of visceral pain in po, Radix Salviae Miltiorrhizae acts directly on the peripheral nerve trunk and cannot block its exciting conduction. This suggests that the analgesic effect of Radix Salviae Miltiorrhizae is exerted via central nervous system.