The joint emission reduction problem in low-carbon supply chain with energy service company‘s involvement was discussed and two game models were established. As a contrast,two situations of low-carbon supply chain were included: cooperative emission reduction RD and energy service company's involvement were included. With the results of the models,we analyzed the pricing strategy and existing condition of the new player,energy service company in low-carbon supply chain and effects of emission reduction of the whole supply chain. Finally the article proved the model results with an example and a sensibility analysis as theory support for low-carbon supply chain with energy service company's involvement.