This study illustrates a process of citizen participation in planning, design and maintenance of Ishikawa River Park in Osaka Prefecture paying specific attention to consensus building among the participants and the administration. Core members of the citizen groups, most of them are from several sects that had opposed to the plan prepared by the administration, played an important role throughout the process. They worked as facilitators to enhance discussion and collaboration within local communities to reach the agreement for conservation of riparian landscape developed along the river. Based upon results of the case study at Ishikawa River Park, it is pointed out that the primary issues of citizen participation process are in attributes of participants and small groups of citizen are more eligible for promoting planning and design of the park, while new members with vitality and expertise are necessary to enhance efficiency in participation.
