It is important to measure quality factor Q in the processing of seismic wave propagation and the predictiing of hydrocarbon. In practical production, the most commonly used to estimate quality factor Q is spectral ratio method. However, the traditional spectral ratio method is facing windowing problem. In this paper, the authors took the advantage of superior time-frequency characteristics of the S-transform and the direct linkage between the Fourier spectrum and the S-transform to extract the corresponding instantaneous spectra of the upper and lower interfaces of the formation. Then by fitting the relationship between frequency and amplitude ratio, the authors estimated the quality factor. Numerical simulation shows the effectiveness of this method.