Abstract: In order to promote the construction of Chinese electricity spot market actively and steadily, it is a gradual evolution path in the initial stage of electricity market construction to start with bidding without price on the demand side, which leads to the question of how to consider the demand elasticity in day-ahead market model. In view of the market operation characteristics in bidding mode without price, the response mechanism of corresponding spot market demand is proposed. The flexible modification of the users’ day-ahead reporting load is studied and security check is carried out based on the modified load to optimize day-ahead generation scheduling model considering demand response. Mechanism of users’ day-ahead bidding behavior and response behavior to price is analyzed firstly. Secondly, the model based method and data-driven method of elasticity revision for reporting load are discussed, respectively. Thirdly, the generation scheduling and security check model based on demand elasticity of load are formulated. Case study based on IEEE 30-bus system is employed to verify the benefits and effectiveness of the proposed mode and method.