Play behavior is a complex form of social behavior, which is proposed to build motor skills and social communication skill in juvenile primates. During a social play, juveniles would adjust their own behavior and strength in order to maintain the play interaction, and therefore build social bonds. Social play interactions also keep juveniles stay in close physical contact and thus maintain social cohesion within group members. I, therefore, hypothesized that play behavior is associated to building social bonds in juvenile Taiwanese macaques. Eight juvenile Taiwanese macaques in the A1 troop at Fushan were observed by focal animal sampling method. In each 10-min focal sample, behaviors of the focal animal were continuously recorded. In addition, behavior sampling method was conducted to collect data on play behavior of juveniles under 3 years old in the A1 troop. Juvenile Taiwanese macaques engaged in significantly more play interactions with kin which were in proximity. Juveniles with same-ranks, of same-sex, or of same-age involved in play interactions significantly more frequently. I concluded that play interactions play an important role on building social bonds in the juvenile Taiwanese macaque.