AIM To investigate the anticonvulsive action of supercritical CO2 ethanol extract from Pinellia Pedatisecta Schott(SEE-CO2PP). METHODS The rat convulsive model was induced by penicillin localized injected in rat cortex. The effects of SEE-CO2PP on the latency of seizure and changes of convulsive behaviors were investigated. The latency of epileptiform discharge, and frequency and amplitude of highest wave in cortex and hippocampus were recorded by using RM6240C multichannel physiological signal collection and analysis recorder. At the same time, the contents of glutamic acid (Glu), aspartic acid (Asp), glycine (Gly) and γ-aminobutyric acid (GABA) in hippocampus were determined with high performance liquid chromatography. RESULTS SEE-CO2PP 15 and 30 g·kg-1, ig, prolonged the latent period of seizure and weakened the extent. SEE-CO2PP also prolonged the latent period of epileptiform discharge, reduced the frequency and decreased amplitude of the highest wave in both cortex and hippocampus. Moreover, SEE-CO2PP increased the content of GABA in hippocampus, but the levels of Gly,Asp and Glu had no obvious changes. CONCLUSION SEE-CO2PP inhibits the epileptiform discharge and convulsive behaviors of convulsive model rats, which suggests SEE-CO2PP has anticonvulsive action.