Abstract: This article elaborates the definition of Poisson Dampening Factor (PDF) in detail and analyzes some characteristics of PDF. Actual application indicated that PDF is very sensitive to the property of reservoir fluid, closely related to water saturation and suitable to be used to detect the property of reservoir fluid and predict water saturation. PDF correlates only to P-Impedance and S-Impedance without explicit density item so that it doesn?t need high angle prestack gather data. Therefore, we can get the relatively stable prestack inversion results under the conditions of common seismic data quality. Actual application in Pinghu area indicated that this technology is a new method for quantitative seismic interpretation with desirable results achieved.