Idiopathic rapid eye movement sleep behavior disorder (iRBD) has close relationship with neurodegenerative disorder. Many researches has validated that almost all of iRBD patients evolved into Parkinson’s disease, Lewy body dementia, or multiple system atrophy over time. However the pathogenesis of iRBD still remains unclear. In this research, VBM and voxel-based DTI analysis were combined to detect the microstructural abnormalities in the iRBD patients. A wide range of changes in brain structure in iRBD group was observed, which may reveal pathophysiologic mechanism on cognitive function disorder，which can be valuable for the early diagnosis and treatment of iRBD.