Idiopathic generalized epilepsy (IGE), accounting for 20–30% of epilepsy, is characterized by widespread cortical hyperexcitability with myoclonic, absence or generalized tonic–clonic seizures. The patients with IGE don’t demonstrate abnormal brain anatomy or an identified focus of seizure activity, but rather widespread atypical cortical activity typified by generalized spike-and-wave discharges and seizures. The classical viewpoint for IGE is that the whole brain may be homogeneously involved, however, converging evidence from brain network analysis clearly indicates that IGE affects extensive brain through specific corticocortical and thalamocortical networks. The prevenient neuroimaging studies have revealed abnormalities in brain networks in IGE during spike wave discharges, little is known about alterations in functional connectivity (FC) of resting state brain networks in children and adolescents with IGE. This purpose of the study is to better understand the pathophysiological mechanisms of IGE in children and adolescents with IGE through investigate FC alterations of thalamocortical network using resting-state fMRI,and investigate to correlation FC alterations with clinical variables including Intelligence Quotient (IQ) and epilepsy duration.The patient group was consisted of 19 patients with IGE( 9 males，10 females，aged 7 to 17 years, mean age 10.73 ± 3.26 years) recruited through Affiliated Hospital of Zunyi Medicine College from March 2014 to August 2015. All patients were diagnosed by experienced pediatric neurologist in accordance with the 2010 International League Against Epilepsy criteria. Nineteen age- and gender-matched healthy volunteers ( male 10 cases, female 9 cases, aged 7 to 18 years, mean age 10.85 ± 3.05 years) were recruited for control group. All subjects underwent MRI examination on a 3.0T MR system (GE 3.0T HDxt, US) with 8 channel head and neck joint phased-array coil. Wechsler Intelligence Scale for children-Chinese Revised was carried out to test every patient by an experienced neuropsychologist on the same day of MRI scanning. Resting-state network date analysis was performed with the DPARSF_V2.3 toolkit which is based on SPM8, and the REST_V1.8 software. Two-sample t tests was carried out to compare the functional connectivity maps of bilateral thalamus between patient group and control group, and correlation analyses between FC strength and clinical variables. Significant differences were set at a corrected threshold of P<0.05 determined by using AlphaSim program.The demographic and clinical characteristics of participants were no significant difference in age, gender composition, or years in education between the patients and controls (P>0.05). Compared to healthy controls, The thalamocortical FC seeding at the left thalamus in the IGE patients showed a significant increase in left inferior temporal gyrus and right supramarginal gyrus, but decrease in left dorsolateral superior/middle/inferior fontal gyrus, left anterior cingulate, bilateral cuneus/posterior cingutate, right dorsolateral superior/middle frontal gyrus (Figure1), whereas, the thalamocortical FC seeding the right thalamus as seed showed a significant increase in right cerebellum, right middle occipital gyrus/superior occipital gyrus, right supramarginal gyrus and left upper postcentral gyrus, but decrease in bilateral dorsolateral superior/middle frontal gyrus, bilateral PCC and right supramarginal gyrus (Figure2). Correlation analysis additionally revealed that IQ positively correlated with FC strength between left thalamus and left anterior cingulate(Figure3) and left dorsolateral superior frontal gyrus (Figure4),and positively correlated with FC strength between right thalamus and left superior frontal gyus(Figure5)Children and adolescence with IGE are vulnerable to suffer from the impairment of cognition functions, including memory, excutive function, and planning, which may be relative to the apparent alterations of functional connectivity in thalamocortcal network between bilateral thalamus and prefrontal cortex. The alteration of FC may reflect the progress of long-term destruction of functional architecture, and may be served as a potential biomarker to examine subtle brain abnormalities in children and adolescence with IGE. Overall, our results suggest that the disruption of FC in thalamocortical network could be an crucial factor for seizure generation and spread in IGE, thus could provide vital and valuable information for better understanding the pathophysiological mechanisms of children and adolescence with IGE.