A huge area of Japan (800 ha, or half the area of Hokkaido) is covered by artificial forests which are either private or local government property. Almost all of these forests were created within the period of rapid growth of economy in response to the increase in demand for woods. However, half of the forests are being ruined without maintenance, because the increase in import of woods makes national forestry weak. Forest researchers have ascertained that artificial forests, which are different from natural forests, lose economic value and public interest if people neglect the maintenance of a forest. However, the loss of the public interest is not apparent in terms of amount. This is the reason the measures to keep public interest in artificial forests is not being emphasized. In the beginning of this research, we estimated the social benefit derived from the maintenance of artificial forests. From this estimation, it is revealed that the positive maintenance of artificial forest is effective. Next, we analyzed current policy on artificial forests from economic viewpoints. From this analysis, it was revealed that current policy by subsidy for national forestry is not enough to recover public interest. Then, we proposed a new policy, which regards the maintenance of artificial forests as one of the substitute policies for public construction like flood control or irrigation, and took its advantages and hurdles into consideration.