EMG (eleltromyographic) signals are generated by contracting muscle and detected in and out side of muscle in the form of random signals. In the measurement of muscle fatigue, the mean frequency of EMG signals using spectrum analysis is an important parameter in diagonosis of muscle disease and in sports medicine fields. In this study, the degree of spectral transfer to lower frequency caused by accumulation of Latic acid inside the muscle is estimated. The new spectral analysis method using 2"d order hAaximum Entropy Method was applied to estimate the mean frequency and we confirmed that this new method yields fast and reliable estimation.tion.