Abstract: AIM: To study the effect of isatin on amygdala-kindled seizure and the anticonvulsant effect in convulsion models. METHODS: The electrophysiological and/or behavioral indices were observed and recorded in the amygdaloid kindling model of rat and several convulsant models of mice, ie maximal electroshock seizure, semicarbazide (SCZ)- and pentylenetetrazole (PTZ)-induced seizures. RESULTS: In fully kindled rats, isatin, tested at doses of 50 to 200 mg.kg^-1 ip, significantly increased the focal afterdischarge threshold (ADT), reduced the seizure severity and the percentage of generalized seizure (P<0.01). In addition, isatin was shown to dose-dependently antagonize maximal electroshock seizure, with ED₅₀ of (123±31) mg.kg^-1. Isatin at the dose of 200 mg.kg^-1 specifically modified the tonic component of sc PTZ or iv SCZ induced convulsion (P<0.01) and thus reduced mortality in PTZ-induced seizure (P<0.05). CONCLUSION: The present data demonstrated that isatin exerted inhibitory effect on kindled seizure in fully kindled rats and on convulsions induced either electrically or by chemicals, indicating that it might possess anticonvulsant efficacy.