Abstract: Spectrum decomposition is the technique to convert seismic signals from time domain to frequency domain, and to provide the opportunity to study the changes in both amplitude and phase in the frequency domain. Resolution of the spectral decomposition can be higher than the results of conventional seismic interpretation, and the response capacity of the signal to different geological bodies are improved. There are great amount of carbonate reservoirs on the Laoshan Uplift in the South Yellow Sea. By comparison of the calculation and application results of the short-time Fourier transform, continuous wavelet transform and S transform of the spectrum decomposition methods, finally we recommended the S transformation as the tool to process the seismic data from the Laoshan uplift. Facts show that this technology may improve the seismic resolution, and help the identification of reservoirs and faults in the studied area.