Objective: To compare the anticonvulsion effect of supercritical-CO2 fluid extractions (SFE-CO2) of Bupleuri Radix

and explore their mechanism. Method: One thousand and sixty mice were randomly divided into 11 groups: RBⅠgroup

RBⅡgroup

RATⅠgroup

RATⅡgroup

ARⅡgroup

UNⅡgroup

PRⅡgroup

SCLⅠgroup

PSⅠgroup

topamax group and NS group. Every group was divided into 4-6 dose groups. The maximal electroshock seizure (MES) was used to observe the anticonvulsion effect. ED50 dose against MES was considered as the administrated dosage to observe the anticonvulsant affects in metrazol seizure test(MET).The rat seizure model was reduced by cortex localion injection of penicillin to investigate the effect of extractions on the convulsant behaviors and hippocampus EEG (the doses were converted by ED95 of MES). Result: ①Except for RBⅡand PSⅠ

all the other seven extractions(PRⅡ

UNⅡ

RATⅠ

PRⅡ

SCLⅠ

RBⅠ

RATⅡ) could dose-dependently antagonize MES in mice. ②All of the seven extractions could prolong the latent period of MET in mice

and the sequence from maximum to minimum was RPⅡ

UNⅡ

RATⅠ

PRⅡ

SCLⅠ

RBⅠ

RATⅡ. The effect of RPⅡ(11.06±4.32)min was better than topamax (9.57±4.47)min.③ The extractions with SFE-CO2 showed a faster onset and shorter duration of he anticonvulsant action than that of supercritical-CO2 alcohol fluid extractions (SAFE-CO2). ④PRⅡ

ARⅡ

UNⅡ

RATⅠ

RATⅡ and RBⅠ could prolong the latent period of epileptiform discharge

reduce the frequency of epileptiform discharge

and decrease the highest wave of hippocampus EEG. Conclusion: ARⅡ

UNⅡ

RATⅠ

PTⅡ

SCLⅠ

RBⅠ

RATⅡ could dose-dependently antagonize MES and MET in mice; PRⅡ

ARⅡ

UNⅡ

RATⅠ and RBⅠ could antagonize penicillin-kindling seizure in rats. PTⅡ may be the most effective extraction in antagonizing the penicillin-induced seizure

and the effect of which may be better than topamax.