This study uses transaction cost theory to analyze the market of rice whole crop silage (RWCS) and obtained the following two results. First, the institutional environment of RWCS market has an effect on transaction costs. The negative influence of RWCS is higher than that of rice for forage. This tendency corresponds to the manner in which livestock farmers get feed. Second, the RWCS market in the city of Katori shows the validity of an intermediate organization for efficient production utilization system. The intermediate organization in the city of Katori mainly serves to reduce transaction costs, which cannot be easily achieved individually. An intermediate organization can process complicated product information similarly and simplify the deal process. The city of Katori and Chiba-ken takes on the roles of providing policy explanations, offering technical information, matching suppliers with buyers, etc. Support from the reliable intermediate organization of the city of Katori and Chiba-ken enabled farmers in the city of Katori to invest in a Total Mixed Rations center and use paddy fields effectively. The price of RWCS in this area is insensitive to the price of both rice and imported feed. One factor behind this unresponsive pricing is the intermediate organization, which works as a system through which rice and livestock farmers obtain long-term benefits. The harmonious RWCS market system in the city of Katori rests on solidarity among rice farmers, livestock farmers, and the local government which strategically deals with the institutional environment.