The study aims at understanding the ecological base of Ainu culture through its utilization of natural resources. This paper represents merely an arrangement of data gathered from old informants during a survey trip to the Saru basin in the summer of 1951, and consists of descriptions of such points as the following : 1) Native knowledge of the characteristics, habits, and distributions of useful plants and animals 2) The division of labor, the seasonal calendar the organization of work, methods and techniques in hunting, fishing, and collecting, and the working of the raw materials. 3) Sorts, uses, and economic values of products 4) Cultural and/or environmental factors conditioning the utilization of resources 5) Ways of maintaining resources