Three types of robot were introduced into classroom environment of nursery school in order to investigate pre-school aged; 4-6 years old child (Human) - personal robot (Robot) interaction (HRI). In this work, entertainment robotic pet; 'AIBO', mental commit seal robot; 'PARO', and communication robot; 'ifbot' were used. Videotaping was carried out for child's behavioral analysis by time sampling method during playing session (30 min.) and considered child's' interaction against robot. By this analysis, it was found that all children interacted gently and negative responses were rarely observed. The consideration how does the child recognize the robot were also presented from the result of questionnaire to child after playing session. It was found that child used to recognize the robot as the meddle; 'artificial emotional creature' between mechanical thing and living thing.