A day ahead dispatching model aiming to minimize the dispatching cost of electric power system considering correlation between the response quality of demand response load and the output of wind power is established. Firstly, a joint probability distribution model of wind power output and response quantity is established. Then, customers’interaction satisfaction index is proposed to limit the adjustable degree of demand response load. Finally, in order to minimize the dispatching cost, an optimal dispatching model is established. The IEEE 39 system standard example verifies the rationality and accuracy of model. The results show that the model proposed can effectively reduce the system operation cost and improve the economic efficiency of the system dispatching.