Abstract: China has launched a national carbon emission trading market to fulfill the emission reduction commitments of the Paris agreement in 2017,carbon quota allocation refers to the eu benchmark method and the historical intensity reduction method. Because the method of historical intensity reduction allocates carbon quotas and changes with time and output and the cost, price and other parameters will change accordingly, so realizing the two-stage supply chain coordination becomes an inevitable problem for manufacturers. Considering a secondary supply chain consisting of a manufacturer and a retailer, the whole sales cycle is divided into two stages. In the first stage, if the order quantity of the product fails to meet the demand, the supply will be partially delayed, and the remaining inventory will be sold in the second stage; in the second stage, market competition, technical update and other factors make the production cost and sales price drop. When the product is out of stock at the end of the period, the retailer will bear the loss of opportunity cost caused by the lack of goods. If there is residual inventory, it will be cleared by residual value. At the same time, affected by the historical intensity reduction method of carbon quota allocation, the carbon emission quota of the two stages is different, and the carbon quota of unit product of the second stage continues to decrease on the basis of the first stage. Manufacturers' carbon emissions in the production process are limited by the government's carbon quota. In addition to meeting the standards through carbon emission reduction input, manufacturers can also buy or sell carbon emissions in the carbon quota trading market.By building a two-stage centralized decision-making system model and a decentralized decision-making system model under revenue sharing contract, the optimal order quantity decision and optimal carbon emission reduction decision of supply chain under carbon quota trading policy are analyzed. The validity of the conclusion is verified by an example analysis based on the data of a smartphone retailer purchasing a mobile phone from a mobile phone manufacturer S. It is proved that the revenue sharing contract can achieve two-stage supply chain coordination by adjusting the retailer's order quantity to reach the optimal order quantity under the centralized decision. Setting lower revenue sharing contract parameters will be more conducive to manufacturers to reduce wholesale prices and take the initiative in carbon reduction. It is found that the historical intensity reduction method is conducive to stimulating enterprises to reduce emissions actively. The greater the reduction of the carbon allowance by the government, the more favorable the enterprise will reduce emissions. On the basis of ensuring the benefits of the supply chain, as much as possible in the early stage of emission reduction input; the lower income sharing ratio between enterprises is more conducive to corporate emission reduction. In previous studies of two-stage supply chain coordination modeling, the variability of carbon quota parameters was not included in the supply chain coordination modeling. In the research of supply chain coordination under the carbon quota trading policy, the cost sharing of emission reduction is still the main task. A few scholars adopted the revenue-sharing contract widely used in enterprise practice, but set the sales price, production cost and other parameters as fixed values, and did not consider that the government carbon quota would be reduced in a ladder-like manner with time and policy changes. In this paper, the above points are taken into account, which can be used for reference in the same type of research.

Key words: carbon cap-and-trade, revenue sharing contract, two-stage, supply chain coordination