Abstract: The anticonvulsant action of Arisaema japonicum BL. has been studied in mice through the following four assay procedures: subcutaneous injection of Strychnine (1.5 mg/kg), Metrazol (90 mg/kg), or Caffeine (600 mg/kg), and supramaximal electroshock seizure test (26 mA, 0.2 sec.). The Arisaema japonicum BL. was injected intraperitoneally in infusum. The LD_(50) in mice was found to be 13.5 g/kg. The result of the present study showed that the Arisaema japonicum BL. (3 g/kg) possesses anticonvulsant properties against Strychnine, Metrazol and Caffeine convulsions (P<0.01 or P<0.05); but no effect on supramaximal electroshock seizure, the tonic extensor seizure of the hindleg was not abolished by the drug.