The New National Comprehensive Development Plan announced by Economic Plan Agency in 1969, pointed the necessity of Regional Administration of Inter-Prefectural problems.The social and economic change of Tokyo Metropolitan Region has brought the needs of various inter-prefectural exchanges and cooperations which would include Bed-Town, Commutation and Housing Construction Circumstances, and therefore, the present prefectural system has become too narrow for effective area development planning which should cover at least 50Km diameter areas. This should be the reason why Regionalism has been insisted by various scholars.I pointed some urgent needs of regional basis administration, especially related with Water Supply, Tokyo Bay Port Administration and Housing of course, which are only some typical cases of Regional Administration.My exprolation was made, compared with Nagoya Port Co-operative, New York Port Authority, and Water Resources Development Corporation and Water Supply Bureau of Tokyo Metropolitan Government. I do hope to promote this kind of functional regionalism for effective regional planning as a first step of regional government.