The purpose of this study was to examine how peer interaction changed on a 5-year-old child with developmental delays. Six picture-book readings were applied in an inclusive preschool classroom, which contained one young child with developmental delays and 28 normally developing preschoolers. A peer interaction checklist was used as an observation guide before and after picture-book readings. After readings, the child with developmental delays was more willing to cooperate with his peers in the situations facilitated by his teacher. Furthermore, the child's leadership was emerging by responding his peers and assigning roles to children.