Abstract: In new electric power systems,wind power penetration level is increasing continuously,thus requiring more peak-regulation capacities. It is necessary to encourage multi type market entities to actively provide peak-regulation services by joint clear of day-ahead energy and peak regulation markets for a purpose of supporting large-scale wind power consumption. This paper firstly analyzes peakregulation capacities and bid rules of multi type market entities,such as coal-fired generators,wind farms and energy storage systems.On this basis,a joint optimization of day-ahead energy and peak regulation is developed,which simultaneously considers deep and startstop peak-regulations of coal-fired generators,wind power curtailment peak-regulation of wind farms and charging peak-regulation of energy storage systems. The optimization attempts to minimize total purchase costs of energy and peak-regulation services subject to technology and bid constraints on market entities,together with constraints on power flow,which is a large-scale mixed integer linear programming（MILP）,and can be solved by the CPLEX solver. The simulation experiments based on improved IEEE 14-bus systems validate the proposed joint optimization of day-ahead energy and peak regulation and its solving algorithm. In addition,benefits of multi type market entities resulting from providing peak-regulation services are analyzed based on the simulation experiments.