Abstract: The estimate of thin interbeds' thickness base d on entropy-spectral p roperties is discussed on the theory in this paper. First the spectrum-equalize d seismic data is equalized by trace, then the result is analyzed with the MESE. I f the resolving power of the MESE doesn't reach the precision desire, the equal ized data is added with appropriate white noise, then is analyzed with the MESE. Thus the more precise spectral estimate is gotten. In this paper,one of the key steps, the maximum entropy spectral estimate (MESE) is ameliorated and it propo ses the method of picking up the period of the spectrum based on the correlation technique and improves the estimate precision of the spectrum period. At last we testify the validity with synthesized seismic data.