Ethosuximide belongs to the second-line drugs among the antiepileptic drugs, with a narrower therapeutic range, and is only used for petit mal seizures and cataplexy. At present, the clinical application of drugs for petit mal seizures include ethosuximide, clonazepam and sodium valproate. Ethosuximide is not as effective as clonazepam, and the adverse effects and tolerability are smaller than those of clonazepam. Since clonazepam belongs to class II psychotropic drugs, it should not be used for a long time, and the course of treatment should not exceed 3-6 months. Sodium valproate is a clinically used broad-spectrum antiepileptic drug, which can also be used in the treatment of petit mal seizures in addition to grand mal seizures, and is not preferred for petit mal seizures due to hepatotoxicity. If the patient’s diagnosis is clear, ethosuximide is the drug of choice for minor seizures.