Maternal deprivation (MD) in rhesus monkeys has been demonstrated to be an effective model to mimicearly adversity in humans because of the close phylogenetic similarity affinity. Although behavioral and hormonalabnormalities have been observed in MD monkeys, the neurobiological underpinning of the long-term deleteriouseffect of MD on monkeys is still unclear. In this study, we assessed emotional changes and socio-behavioralabnormalities induced by long-term MD and assessed structural alterations of gray matter volume (GMV) andwhite matter integrity (WMI) in 15 MD rhesus monkeys and in 15 age-, gender-matched normal controls (NC) usingvoxel-based morphology and voxel-based analysis methods. We found increased stereotypical behavioral dura-tions and decreased social grooming durations in MD monkeys. Reduced GMV in the primary visual cortex (V1)and increased fractional anisotropy (FA) in the left posterior superior temporal sulcus (pSTS) was also found inMD monkeys. Moreover, the mean FA values in pSTS showed positive correlation with the stereotypical behav-ioral durations in MD monkeys and negative correlation with social grooming durations in NC monkeys. Our find-ings indicated that the deleterious effects of MD on rhesus monkeys resulted in structural abnormalities in thevisual cortex and premature myelination in the pSTS. These findings provide new insights into understandingthe impact of maternal deprivation on the neurological basis of brain development. ? 2018 Published by ElsevierLtd on behalf of IBRO.