Abstract: Objective To study the effect of saikosaponins on the electroencephalogram (EEG) of epileptic rats to evaluate its therapeutic effect against epilepsies. Methods Sixty 8-week-old healthy SD rats were randomized into normal control group (A), epileptic model group (B), lamotrigine group (C), and 3 saikosaponin groups of small, moderate and high doses (D, E, and F groups, respectively), with 10 rats in each group. Penicillin was used to induce epilepsy in the latter 5 groups, and the EEG and onset of epileptic seizures were observed in each group. Results In group B, the EEG contained obvious epileptic discharges, which were not found in that in group A. After treatment with saikosaponins and lamotrignie, the EEG of group C and F became normal, whereas the EEG in group D still contained epileptic discharges at a low level, and that in group E was basically normal. The EEGs of group C, D, E, and F were significantly different from that in group B (P<0.001). Conclusion Saikosaponins can obviously alleviate the severity of epileptic seizure in epileptic rats.