The seismic reflection coefficients are influenced by various factors in fracture/vuggy Ordovician carbonate formation in the Tahe oilfield. An Equivalent Porosity Model was defined as the function or P-impedance from well logs, and geostatistical seismic inversion was carried out to get large numbers of high resolution P-impedance realizations. The co-simulation between P-Impedance & Equivalent Porosity was constrained by well logs which were sparse in spatial domain. The model successfully illustrated the inhomogeneous feature of the carbonate reservoir, and it passed the critical blind well testing. The model was also helpful to understand the flowing feature of the production wells. This study provided a quantitative way to use surface seismic in the reservoir modeling for the fracture/vuggy carbonate reservoir.