This study was to find out if forest activities affect to children with ADHD and improve their behaviors and social natures. 14 Elementary school students were divided half and designated either experimental group or control group after the preliminary work. Both two groups took prior examinations at the beginning of the program. To the experimental group, forest activity program had been implemented once a week, from 10 a.m. to 12 p.m. for 10 weeks at the woodland path in K Park operated by Seoul city. The results proved to be effective in some lower areas of CPRS and Fair test. Additionally, scores of SSRS increased a bit in all four subdivisions within social indicators, but they were not meaningful in statistics. But the score increases of open area in the scales of PACI were meaningful. Taken together, it indicates that the application of forest activity programs including forest games is highly applicable and efficient supportive treatment for ADHD children.