This paper gives the results of measuring-shaft-horsepower and torque-fluctuation of the intermediate shaft with the magneto-striction type torsionmeter, which is a partly improved one of the shaft-horsepower-meter previously reported. The principal results obtained are summarized as follows: 1. The value of shaft-horsepower measured with this new torsionmeter on the sea trial coincides not only with the value calculated from the indicated-horsepower simultaneously measured but also with the model basin prediction when it is standardized. 2. The stress on the intermediate shaft due to the torsional vibration is not so large at the usual condition.