This study was performed so as to examine whether the friendship relation with peers has influence on children\'s learning theory of mind on 87 children\'s of 35 years old. Experiment was performed with true belief task and false belief task, the contents of task(food A and toy B), friendship context and strange context. As the result of study, there were more children\'s who passed through true belief than children\'s who passed through false belief task. In addition, it is suggesting that the friendship with peers may play useful role for understanding the mind of others through high performance result in friendship context performance in strange context. In addition, high age showed high performance, and that difference among 3 years old, 4 years old and 5 years appeared as the result of post test showed that there is possibility that theory of mind may develop remarkably after 4 years old.