This paper analyzed firstly the positive meanings of imperfect competition, diversification of quality concept and role of various actors, and secondly the complicated procurement activities by Japanese food-related firms. Though quality control systems for vegetables have been strengthened after pesticide problems happened in China, they still remain partial. It is a crucial task for food-related firms to establish a supply chain based on trust. Long delivery time and large lot size are inevitable for imported products. As far as Japanese food-related firms express an orientation for postponement procurement, Japanese agricultural products can gain the competitive advantage of physical distribution quality. On the other hand, as there is a case that imported agricultural products are positioned as a means of differentiation strategies, any quality advantage depends on each food-related firm's strategy.