Abstract: Absorption coefficient is an important parameter in the reservoir description and hydrocarbon prediction. It is very sensitive to the variation of lithology. The spatial distribution of formation absorption coefficients which are estimated from horizon interpretation of seismic data plays an important role in improving accuracy of reservoir description and hydrocarbon prediction, and can be used to delineate hydrocarbon distribution and estimate reserves when combines with other seismic data, log, and geologic data. It is difficult to extract absorption coefficients directly from seismic amplitude due to the distortions in amplitude and waveform. To overcome the above-mentioned problems, this paper proposes to inverse formation equivalent absorption coefficients with spectral modeling. The geologic meaning of formation absorption coefficients, the parameters characterized formation absorption properties, and the inversion method used here are presented. The applicability of the method is illustrated with real data.