The purpose of this study is to examine the impact on social competence and peer interaction of infants, by developing the forest play program with the infants and mothers and applying this to the infants. For this purpose, the objectives and educational contents of the program were selected based on the literature review, and the program was developed through expert consultation and preliminary research. This program is designed to enable the infants to grow and develop holistically, by using the five senses to explore nature and play freely in the forest with their mothers. In order to verify the effectiveness of the program, 17 infants, who participated in the forest activities at the B center located in A city, were studied and 10 forest activities were conducted for 10 weeks. Statistical analysis of the study was performed using the SPSS WIN 21.0 program. The results of the study showed that the forest play program with mothers positively influenced the improvement of social competence and peer interaction of the infants. Therefore, it can be seen that the forest play program with mothers is effective to improve the social competence and peer interaction of the infants. These results suggest that this program is worthy of applying to the educational field.