This research is understanding how cooperation play therapy program using picture books affects communication ability and prosocial behavior. The subjects of study are 3 men. One is 5 years old, another is 6 years old and the other is 7 years old. They cannot participate cooperative play and lack a sense of verbal and social interaction with peer relationship. The research problem is whether the therapy is effective on improving their communication ability and prosocial behavior. Study tools are following. First, a measurement tool containing a survey of teacher rating is used to measure the communication ability. Second, Prosocial Behavior Scale for Young Children(PBSYC) is used to measure prosocial behavior developed by Kim(2003). This program is constructed by introduction, deployment and ending. Picture books are very useful in terms of development and are more effective media than other media, and they have a merit that they can be universally used in home and educational institutions, which is a great value for educational use. Literary experience conveys a variety of emotions, enriches emotions, satisfies curiosity, inquisitiveness, and wonder, and emotional stability for adults and infants. The results of the study showed that the cooperative play therapy program using the picture book was effective in the linguistic and nonverbal communication behaviors, and the program was effective in prosocial behavior as a whole.