This paper focuses on the process for distribution of irrigation water in one of the Land Improvement Districts (LIDs) in Kagawa district of Japan, Marugameiino LID, in the dry period of 1994. Though Japanese LIDs can be regarded as successful cases of Participatory Irrigation Management (PIM), there are several specific conditions to make LIDs' self-governing management work in practice. In the case of Marugameiino LID, there are two ways to explain the efficient distribution process ; one is the result of the Common Pool Resources (CPRs) management for a small community, the other is part of a larger modern water-supply system. Too much emphasis on the former might be inappropriate for defining the role of Water User's Association (WUA) and Water User's Group (WUG) in developing countries.