The life of aircraft structure is determined by calendar life in the service circumstances for the lower flight time per year of the aircraft. The method of determining the calendar life based on annual flight frequency is proposed according to the conclusion of pure fatigue life in this paper. The residual calendar life of aircraft varing with annual flight frequency is obtained by modifying the parking corrosion influence factor （C） and the flight corrosion fatigue influence factor (K). The corresponding test is carried out and the results show that the proposed method not only can determine the calendar life of aircraft under given annual fight intensity ， but also can provide a feasible method to control and delay the calendar life of the service aircraft.