The drift flux model proposed by Zuber and Findlay is based on the difference between the local velocity of each phase and the local velocity of the center of volume. On the other hand, modelling of multiphase flow was carried out in this study based on the velocity difference between the local velocity of each phase and the local velocity of the center of the other conservative quantities: mass, momentum and energy. The derivation of basic equations of the present models were carried out referring to that of the drift flux model. As a result, new relations were deduced among the areaaveraged mass, momentum and energy fluxes of the mixture, the local volume fraction weighted mean velocity of each phase, and the macroscopic velocities of the center of conservative quantities. The usefulness of the proposed relations was confirmed using the experimental data for gas-liquid-solid three-phase flows in vertical pipes.