Objective To probe the relationship between the connectivity of premotor area detected by resting state functional MRI and stereotyped behavior of ASD.Methods 39 children patients with ASD and 42 healthy controls with matched age,sex and IQ were recruited.All the 81 subjects performed scaling with behavior scale index and underwent resting-state fMRI scans.After the fMRI data precession,the premotors in left and right sides were selected as ROI seeds to perform functional connectivity.Results Compared with healthy controls,children patients showed significant increased connectivity between the left premotor area and posterior cingulate cortex,as well as decreased functional connectivity between the left premotor area and the left insula.In addition, a negative linear correlation was showed between the connectivity of the left premotor and the insula and the behavioral scores.Con-clusion Imbalanced premotor functional connectivity may be one possible mechanism of stereotyped behavior of ASD,representing an attention deficit and/or impaired sensory perception to the external salient stimuli.