ObjectiveTo study the intelligence quotient(IQ) profile of the children with idiopathic generalized tonic-clonic seizure (GTCS) and the factors influencing IQ of them.MethodsAll 28 children with GTCS were selected who were aged 9 ～ 16 years in 20 GTCS families in a mountain area of the south of Anhui Province,all available healthy siblings of the children included in the epilepsy group,did not have epilepsy,and were nearest in age to the children with GTCS ( control group 1 ),and thirty children aged 9 ～ 16 years old who had lived in the same village ( control group 2) entered into our study.The IQ was studied of the three groups of children and the factors influencing IQ of children with GTCS at the same time.The data were input SPSS12.0 and analyzed.ResultsThe IQ of children with GTCS(85.64 ±20.57)was lower than that control group 1( 103.39 ± 11.17)and the control group 2 ( 106.17 ± 11.67).The difference between children with GTCS and the two control groups were significant for almost all the subtest quotients except completion of drawing and picture arrangement.No significant differences were found between the control group 1 and the control group 2 on the IQ and the subtest quotients.IQ scores of children with GTCS showed significant linear correlation with father's education( r=0.453,P＜0.01 ),age at onset of epilepsy( r=0.506,P＜0.01 ),duration of seizure disorder( r=-0.533,P＜0.0l ),status epilepticus( r=-0.732,P＜0.01),total number of seizures( r=-0.761,P＜0.01) and seizure frequency ( r=-0.708,P ＜ 0.01 ).ConclusionThe IQ scores of the children with idiopathic GTCS are lower significantly than general children population.Epilepsy-related variables affecting IQ scores of the children with idiopathic GTCS are duration of seizure disorder,status epilepticus,age at onset of epilepsy,total number of seizures,seizure frequency.