Abstract: Environmental labeling is an important way to help companies declare the green quality level of their products. The self-posting and certification environmental labeling strategies are considered, the environmental labeling strategies selection of a green supply chain consisting of one manufacturer and one retailer is studied, and further the impact of cost-sharing contracts on green supply chain decisions is analyzed. Research shows that when consumers’ green awareness or trust increases, the green effort level of manufacturers and retailers will increase, but the increase in consumer green awareness is not always beneficial to manufacturers. Under the certification label strategy, the manufacturer’s profit will decrease with the increase of consumers' green awareness. From the label selection, the manufacturer will always choose self-labeling strategies, especially under the manufacturer’s cost-sharing contract, the highest profit will be obtained, but the retailer’s profit under the certification label is higher. Comparing the efficiency of contracts, all cost-sharing contracts can increase the level of green efforts in the supply chain and promote the increase of the manufacturer’s profits and overall social benefits, but they are not necessarily beneficial to the retailer’s profits. Especially in the certification labeling strategy, the cost-sharing contract will be invalidated, and under the self-labeling strategy, the retailer’s cost-sharing contract can achieve coordination of the supply chain. From the perspective of total social welfare, only when consumers’ environmental awareness, trust, and certification cost are high, the social welfare under the self-labeling strategy will be higher than the certification label strategy, otherwise certificate label strategy will be better.

Key words: green supply chain; self-labeling; certification label; cost sharing contract