Abstract: The advantage of maximum entropy method(MEM) of spectral analysis is that it gives finer resolutions and less peak discrepomcy than the conventional spectral analysis. MEM is particularly useful for short data lengths and long period spectral analysis. It bears special signi ficance for periodic analysis of climate and medium-range and long-range process. The order of the coefficient of MEM prediction error may be determined by the order of the former minimum under the condition that the power of the former minimal final prediction error of spectral estimate is consistent with the latter.