Abstract: Although energy,regulation and operating reserve are from different markets,they are provided by the generator or load of participating demand response.Since some of the providers can provide a variety of services simultaneously,the effect of the method of co-optimization of energy,regulation and operating reserve is undoubtedly better than orderly optimization.Based on an analysis of the typical American electricity market operation rules,a mathematical model for the co-optimization of energy,regulation and operating reserves is given in this paper.The clearing price of the regulation and operating reserves is derived,the opportunity cost is analyzed under different conditions where the capacity constraint is binding,the demand curve is introduced to limit the scarcity price of the operating reserves.It is seen through the analysis that the method of cooptimization of energy,regulation and operating reserve is able to yield better optimization results.