The concern with realizing recycling society has been growing. For realizing recycling society, considering both profit of companies and environment load is important. It seems that the decision-making of collection trader is important, and the life of product has much effect on the decision of collection trader. In this paper, computer simulations based on Multi-agent System are executed, and the relationship between decision-making of collection trader and life of product is analyzed in the point of both profit and environment load.