The sandstone of the second member of Shanxi Formation in Zizhou Gas Field is characterized by thin reservoir and quick lateral variation. Based on the poststack seismic reservoir prediction, the method of prestack seismic reservoir prediction is studied and applied. The prediction accuracy for the effective reservoir can be improved by using prestack inversion to calculate elastic impedance and elastic parameters. The application of this technique in the reservoir prediction in Zizhou Gas Field shows that the prediction coincidence rate is raised, and that it takes a significant part in the development in Zizhou Gas Field.