The hydrodynamic interaction between a submerged non-lifting body and lifting bodies, i.e., hydrofoils, is studied. So far it has been confirmed that the hydrofoil producing the downward lifting force reduces the wave resistance drasticly due to the hydrodynamic interaction with the non-lifting body. This paper investigates the hydrodynamic interaction effect on the unsteady hydrodynamic forces, the added wave resistance and the wave field through model test and numerical computation by Rankine panel method. Numerical results and experimental results are compared and the hydrodynamic interaction effect is discussed. We have found good agreement between numerical and experimental results and it has been confirmed that the interaction effect is not so significant in the present case.