Abstract
The purpose of this study is to show the support functions for cooperation in the river basin. This paper analyzes about the opinions hearing from the experts of water problems and key persons of cooperation in the river basin. It shows there are 3 points about validity of cooperation in the river basin. The results of structural analysis by method of ISM show substantial problems and measures to promoting cooperation. Finally, 9 functions for supporting cooperation in the river basin are constructed, and those necessary conditions and mutual relations are shown also.