The developmental mechanism underlying the brain development abnormalities in attention deficit hyperactivity disorder (ADHD) is still unclear. The currently developed synthetic MRI (SyMRI) offers a novel approach for brain segmentation and myelin volume estimation. Our study investigated the profiles of brain volumetric measurements in children with ADHD with both SyMRI and conventional T1 weighted(cT1w) MRI. And the results proved the global brain development retardation but normal whole brain myelination of children with ADHD. Besides, the high consistency of brain segmentation with cT1w image and SyMRI has also been proved, which indicate the clinical feasibility of SyMRI in children.