POOL,NETA and PJM electricity markets are taken as examples to analyze the cost coverage in the process of electricity production. In the part of cost coverage, the cost generation and corresponding way of cost coverage is analyzed from two aspects: user and dispatch. Then the overall characteristics, advantages and disadvantages of the three transaction modes form the perspectives of the complexity of the transaction and charging system, the organization of the market, then stability and guidance of the price, and the transparency of the market operation are analyzed respectively. At last, on the basis of the research, the related suggestions are given, combined with the national conditions in China.