In thinking about an improvement of a performance in swimming, it is important to progress the self-propulsive force in swimming. The purpose of this study was to develop the equipment and procedure, which measured and evaluated by 3 type of swimming as follows ; Semi-tethered swimming (STS), stream swimming with water flow and STS with water flow. From the basis of these results, the mutual relations between swimming velocity, propulsive force and resistance in swimming were considered.