: Supply chain coordination is the fundamental means to improve the supply chain’s overall profits and the interests of all parties． The goal of this paper is to investigate the coordination strategy of dual channel supply chains in which a manufacturer has diseconomies of scale of production． The paper shows the market prices and overall profit of dual channel supply chains in centralized decision-making and the design method of wholesale price contract and revenue sharing contract in decentralized decision-making． The concept of coordi-nation degree is proposed，which represents the degree a contract coordinates the supply chain． It is proved that if the coordination degree of wholesale price contract is less than 1，coordinating of the supply chain can-not be achieved，and that if the coordination degree of the revenue-sharing contract is equal to 1，relative to the wholesale price contract，the revenue sharing contract cannot improve the profits of retailers and manufac-turers，resulting in an unenforced able revenue sharing contract． In order to find the enforceable coordination strategy of the dual channel supply chain，the paper puts forward the design method of the revenue-sharing contract with fixed compensation which is determined by Nash bargaining negotiation model． The results show that the coordination degree of the contract is equal to 1，and that，compared with the wholesale price con-tract，the contract can also improve the retailer’s and the manufacturer’s profit． In addition，the study also shows that: the diseconomies of scale elasticity coefficient is proportional to the sales price and inversely pro-portional to the overall profit of the supply chain; the more intense the competition between different channels，the higher the selling prices，the demand，and the earnings of the dual channel supply chain． Furthermore， the revenue sharing contract with fixed compensation can also coordinate the dual channel supply chain with linear costs． Finally，the correctness and effectiveness of the conclusion are validated by numerical examples．