This study explored the associations between maternal meta-emotion philosophy (MEP) and maternal socialization of preadolescents positive and negative affect. It also investigated whether adolescent temperament and gender moderated this association. MEP involves parental awareness and acceptance of their own and their child s emotions and their coaching of child emotions. Event-planning (EPI) and problem-solving (PSI) interactions were observed in 163 mother-adolescent dyads, and maternal behaviors were coded to provide indices of socialization responses to adolescent emotion. In addition, maternal MEP was assessed via interview, and preadolescents provided self-reports of temperament on 2 occasions. Maternal MEP that is higher in awareness and acceptance was associated with reduced likelihood of negative socialization behaviors during the EPI. Moreover, preadolescents temperamental negative emotionality (NEM) and effortful control (EC) moderated some of these MEP-socialization associations. During the positive EPI task, greater maternal awareness and acceptance is associated with reduced likelihood of negative socialization toward preadolescents with easy temperaments, that is, low NEM or high EC. However, during the conflict task, greater maternal awareness is associated with reduced likelihood of negative socialization among preadolescents with difficult temperaments. Some male-specific associations were also found.