We investigated the effectiveness of the CAI teaching aid by a trial test given to university students. The results are as follows: 1. Over 70 % of both male and female students understood each picture of the CAI aid. 2. Experience of child development education, playing with children, interest in children and the study of child development hardly influenced in understanding pictures of the CAI teaching aid. 3. Pictures concerning emotional and social development made a good impression on students. 4. Students approved the effectiveness of the CAI aid. 5. Students became more interested in children by the CAI aid.