Abstract: In nuclear Power Station,the purpose of the forecast of shutdown date for reactor fuel cycle and evaluation of fuel cycle length is to provide the input for the fuel management.Two methods for the fore-cast of shutdown date for fuel cycle,including their scope of application,are introduced in this paper.Calibration method of cycle length is also introduced in this paper.Several cycle lengths are evaluated by using the calibration method.At the end of this paper,error of calibration is analyzed..