A new approach for governor system parameter identification based on the measured frequency curve is presented. Firstly, an input-output model of governor system is established and the identifiability of corresponding parameters is confirmed. Then the simulated frequency curve of the disturbed power system is acquired by directly invoking PSASP（Power System Analysis Software Package）electromechanical transient simulation module through an interface design. Governor parameters of generation system are iteratively adjusted to optimally match the simulated frequency curve with the measured frequency curve using PSO (Particle Swarm Optimization) algorithm, thus governor system parameter identification based on the measured frequency curve is realized. Simulation results of an actual power system illustrate the feasibility and efficiency of the proposed method, meanwhile application of PSASP is extended through the designed interface.