Abstract: A multi-increasing step mathematics model for the estimation of the largest.earthquake magnitude in coming period has been set up by a new dynamic system prediction method to be presented in reference No.1, of which the selected several input variable are the seismic fre-quency, the converted frequency and the magnitude interval et al.The estimation for furure seismic trend in North China has been made by this model.A comparison between the results by this method and the fixed parameters prediction method has been shown in this paper.Be-cause of the full consideration of the temporal variation of the system in the prediction pro-cess in this method, the larger error caused from fixed parameters in the general prediction method would be overcome to improve the quality of the earthquake prediction.