Abstract: In order to make prediction of gas hydrate distribution and occurrence, wave impedance inversion was adopted to process the seismic data from the gas hydrate survey in Sotheast Hainan Basin in this paper. At the very beginning, a low frequency impedance model was established by high resolution interval velocity inversion which depends on precise velocity analysis; then, two inversion methods, the direct inversion based on Born's wave equation and the indirect inversion based on model optimization, were used for impedance inversion. The results show that the wave impedance of seismic data in the study area is easy to be distinguished for geological interpretation, and the distribution of gas hydrate was sound and clearly described. In case there is no well logging data, wave impedance inversion could be used to study gas hydrate and is practical to gas hydrate exploration in the future.