This paper explores the organization of foraging territories of populations in early Upper Palaeolithic northeastern Japan. First, a chronology is established for the region, outlining three stages known as chronological stages 1 to 3. This is followed by a discussion of the role of trapezoids and knife-shaped blades, lithic raw materials (especially locally available siliceous shale), and their environments in understanding lithic technology, food procurement strategies, and lithic resource exploitation in each chronological stage. Various site types are categorized by examination of tool composition, procurement and consumption of foods, and lithic raw materials in each site. The results of this analysis indicate that foraging territories have been reorganized three times, corresponding with each chronological stage. Transformations in foraging territories are associated with changing tool types, lithic technology, exploitation of lithic raw materials, and food procurement strategies, representing the adaptation of human populations to environmental fluctuation in early Upper Palaeolithic.