A statistical-mechanical-based equation of state (EOS) for pure substances, the Tao-Mason equation of state, is successfully extended to prediction of the (p-v-T) properties of fourteen natural gas mixtures at temperatures from 225 K to 483 K and pressures up to 60.5 MPa. This work shows that the Tao-Mason equation of state for multicomponent natural gas is predictable with minimal input information, namely critical temperature, critical pressure, and the Pitzer acentric factor. The calculated results agree well with the experimental data. From a total of 963 data of density and 330 data of compressibility factor for natural gases examined in this work, the average absolute deviations (AAD) are 1.704% and 1.344%, respectively. The present EOS is further assessed through the comparisons with Peng-Robinson (PR) equation of state. For the all of mixtures Tao-Mason (TM) EOS outperforms the PR EOS.