In a public design, such as a landscape, it is important that the information on the design process be shared among the planners, the administration, and the citizens, and to continue the design work with consensus. A landscape design proposal cannot be reasonably evaluated from only the result of a design since the decision making process would not be sufficiently explained. Therefore, designers are required to record and store several design documents during the design process. The development of a knowledge management technique is desirable in order to facilitate the sharing of the project information in the designer’s group. The authors have researched knowledge management in a landscape design process, developed a heuristic knowledge-sharing tool that aids decision-making by consensus in a design process. This tool is a sheet system based on XML (extensible markup language). It allows the user to retrieve knowledge from a similar design project, and to customize the formats of a sheet according to the design process.