The purpose of this study was to investigate the moderating effect of negative emotionality on the association between mother-child intimacy and peer acceptance based on differential susceptibility model. According to differential susceptibility model, negative emotionality and difficult temperament is potential differential susceptibility factors. The participants were 3-year-old children recruited from preschools and daycare centers. Teachers completed measurement of negative emotionality. Peer acceptance was measured by peer nomination. Mother-child intimacy was reported by mothers. The results presented that negative emotionality significantly moderated the relation between mother-child intimacy and peer acceptance only for boys. For boys with high level of negative emotionality, mother-child intimacy significantly predicted peer acception. However, for boys with low level of negative emotionality, mother-child intimacy did not associate with peer acception. For girls, negative emotionality did not significantly influence the association between mother-child intimacy and peer acceptance. These findings support differential susceptibility hypothesis that vulnerable children are susceptible to positive parenting effects.