A new propulsion test method i. e., propeller loading test system which is based on the theoretical consideration about hydrodynamic interaction problem, has been developed in the Ship Research Institute. The propulsive performance factors of a ship are presented as the function of propeller thrust loading in this method. By making use the interaction calculation of the proposed method, it is possible to estimate the propulsive performance before the tank test. Three ship models of stern form variation were designed. Applying the new method for the models, tank tests were performed. And the test results were examined by means of this test system. Effectiveness of use of the method is demonstrated in this report from view points of stern form improvement and detailed analysis of propulsive factors is also presented.