The study of horticultural activity program was conducted to community child center children to analyze the effects of the program on children’s emotional regulation ability and self-expression. The subjects of this study were 10 children (5 boys and 5 girls) sampled from H Community Child Center in K City. The horticultural activity program was executed twice a week and a total of 12 sessions during the period from July 4 to August 22, 2014. The results of this study were as follows. In the results of the emotional regulation ability test the mean score increased significantly from 57.0 before the horticultural activity to 63.0 after (P=0.005). In the results of the self-expression test the mean score increased significantly from 67.2 before the horticultural activity to 71.1 after (P=0.008), and among its sub-factors, the content element was changed significantly. The results of this study confirmed that horticultural activities for community child center children have a significantly positive effect on their emotional regulation ability and self-expression.