Biodiversity-friendly farming is an innovative practice that is adopted by not only individual farmers but also rural communities as a whole. The objectives of this paper are to outline the diffusion process of the biodiversity-friendly farming adopted by rural communities, which is accompanied by collective decision-making, and to reveal which attributes of the rural community influence the adoption level of the farm ing. To this end, a case in a Japanese rural region was studied. The study concluded that the adoption level of biodiversity-friendly farming in rural communities is promoted by higher ratio of middle-aged population, higher degree of social capital accumulation through community meetings, a greater number of neighboring rural communities adopting the farming, and the sale of rice as a branded commodity.