In order to simplify the technique of ship motion model tests in oblique waves, it is proposed to carry out towing model tests using a measuring apparatus of 5 degrees of freedom which supports sway and yaw motions with linear springs. This technique enables the model tests in oblique waves to be performed more efficiently comparing with the tests using a free running model. Moreover, phase lag measurements with regard to encounter waves have a good accuracy because the surge motion is fixed in this guidance system. Meanwhile, towing conditions in these tests are similar to the assumptions of the theoretical calculation based on the Strip Method. Therefore this test is suitable for the direct comparson between experiments and calculations. Though it is unavoidable for measured data to be affected by this guidance system, it is possible by some pre-calculations to estimate the degree of its influence and to select a optimum guidance system. Accordingly the guidance system which is planned appropriately has a very small influence for measurements. In conclusion, this guidance system is recommended to be used routinely. Using this guidance system, model tests in oblique waves were executed for a container ship model which was adopted as the ship form for the comparative calculations of the ITTC. Successful experimental data about ship motions and 5 components of wave-induced loads were obtained. The results of comparison between model tests and theoretical calculations revealed that there were some discrepancies and that further investigations on details of the Strip Method should be carried out.