Abstract: This paper proposed a new approach of system frequency regulation mode, which was based on the unified calculation, overall allocation, hierarchical dispatch and step control principals. The modeling method of specific enclosed operating area was introduced in this paper and directly dispatched generating units of general load dispatch center, which had strong regulating capacities and large regulating capacity in the hybrid power generation system, were utilized to participate in the process of system frequency and tie-line active power regulation. Corresponding coordinated regulation modes of general load dispatch center and provincial operating areas were also introduced in this paper. Actual statics of the frequency performance before and after the new mode was introduced to the power grid.