Action potential (AP) conduction in nerve fibers plays an crucimportantal role in transmitting nociceptive information from the periphery to cerebral cortex. It is possible that analgesics depress nernerve AP conduction, inhibition resultings in antinociception. algesia. Many of analgesics are well-known to suppress nerve AP conduction and also voltage-sensitivegated Na+ and K+ channels involved in AP conduction. Compound action potential (CAP) hrecorded from as been used bundle of nerve fibers is a measure to know whether nerve AP conduction is affected by analgesics. This review article mentions the inhibitory effects of clinically-used analgesics, analgesic adjuvants and plant-derived analgesics on fast-conducting CAPs and voltage-gated Na+ and K+ channels. Their effects were compared in efficacy among the compounds and it was revealed that some of them have similar efficacies in suppressing CAPs. Nerve AP conduction inhibition produced by the analgesics is suggested to contribute to at least a part of their antinociceptive effects.