Abstract: This paper constructs a closed-loop supply chain model composed of a manufacturer and a retailer. Based on the Stackelberg game theory, this paper studies the pricing decision of the closed-loop supply chain under the situation of retailer's sales effort and different subjects undertaking corporate social responsibility (CSR), and analyzes the influence of sales effort effect and social responsibility behavior on enterprises' decision-making and profit. The results show that the retailer's sales efforts are conducive to reducing the wholesale price and improving the demand and the recovery rate of waste products; the CSR behaviors of different agents are conducive to stimulating the demand of the supply chain and improving the level of sales efforts and the recovery rate. Compared with the model without CSR, when the manufacturer or retailer assumes CSR, they will suffer loss of economic benefit, but the stakeholders will gain more economic benefit, and finally the supply chain will benefit from higher overall profit and better social utility.

Key words: closed-loop supply chain, corporate social responsibility, retailer sales effort, pricing