We examined the association between mother–child attachment and social withdrawal in Chinese urban children. Participants in the 1.5-year longitudinal study were 142 Chinese children (74 boys, 68 girls), who were initially aged between 6 and 10 years. Self-reported mother–child attachment style was measured at Time 1 and Time 2. Two subtypes of social withdrawal (i.e., shyness and unsociability) were measured by self-rating and peer nomination at Time 2. Regression analysis showed that attachment style predicted a different subtype of social withdrawal. Early secure and ambivalent attachment were associated negatively and positively, respectively, with self-reported shyness. Current (Time 2) avoidant attachment was positively associated with both self-reported and peer-rated unsociability, whereas current ambivalent attachment was negatively associated with self-reported unsociability. The findings underscore a specific connection between attachment style and social withdrawal subtype.