The purposes of this study are to develop a water saturation model (MCRM model) for a formation with conductive rock matrix and to calculate the empirical parameters used in the model by using the optimization method. The empirical parameters in the new model (MCRM model) include the conductive formation parameter (b'), tortuosity factor (a), cementation exponent (m), and saturation exponent (n). A field data is used to illustrate the procedures to derive the empirical parameters from three models, the MCRM model, the Givens model, and the Archie equation (model), are compared. The conductive formation parameter (b') for the field data analysed is less then one, indicating that the formation contains conductive rock matrix.