This study examined the relationship between attachment style and emotional suppression. Participants included 115 Japanese high school students （62 males and 53 females）．Attachment styles of participants were measured with the Internal Working Model Scale （Toda, 1988），based on the secure, ambivalent, and avoidant factors. The scores were compared with the Emotional Suppression Tendency Scale（ Kashimura and Iwamitsu, 2007）; pleasure and anxiety were especially focused on as they relate to attachment style and emotional suppression. The collected data was analyzed. The results indicated that insecure and avoidant attachment styles tended to suppress emotions of pleasure and anxiety. In contrast, ambivalence in attachment did not affect the expression and suppression of emotions. These results could be potentially useful in adolescents’ school counseling and psycho-education .