Demand response (DR) is considered to be one of the most incentive smart grid functions to enhance power system reliability and control. For the purpose of system security, DR has been utilized to deal with contingent events. In this way, load shedding conducted by the DR program is no longer sorely considered as the last defense line to save system frequency, it should be considered as part of the available fast response resources to cooperate with spinning reserve for balancing generation and demand under some specific conditions. This paper proposes an overall frequency restoration plan considering the DR and spinning reserve. The frequency restoration is designed using the DR as the first option to intercept frequency decline for a large disturbance, followed by the scheduled spinning reserve to raise frequency back to the pre-disturbance level. The proposed scheme is especially developed to intelligently deploy DR for coordinating with different spinning reserve constraints and contingency scenarios. Tests of the proposed frequency restoration scheme are evaluated by simulation where the system data was retrieved from frequency events in a utility. Test results show that the proposed spinning reserve and DR deployment could effectively restore frequency under various contingency scenarios.