Abstract: Pinghu formation in Pingbei K gas field is semi-enclosed bay facies sediments deposited in Xihu sag of the East China Sea. The reservoirs are buried deeply, on which compaction effect was obvious. In addition, P impedance of sandstone and mudstone is overlaid. With the help of S wave data, well logging plane normalization and rock physical analysis, it is considered that Vp/Vs could be used in reservoir identification. By pre-stack simultaneous inversion, reservoir prediction has been conducted for Pinghu formation of K gas field. By overlaying with the reserve calculation line, the reservoir prediction results have been used for pre-drilling optimization of production wells in K gas field.