In this paper the power spectral density of p-adic stationary stochastic prosess under the sence of Chrestenson transform and its maximum entropy estimator are studied. The relationship formula between the power spectral density and the entropy rate and the normal equations of maximum entropy spectral estimator which is expressed in finite form are obtained. When the number of sampling data is p
the maximum entropy estimator can be directly expressed by the known finite autocorrelation data. These results are much different from those of Fourier’s.