Rowing is composed of many equipments, which are a hull, a stretcher, a sliding sheet, riggers, oars and so on. There are many parameters which have influence upon hull velocity or mechanical efficiency. The simulation which calculates motions of the hull and the oar by using input of rower's motion and the force which pulls the oar handle can be used to estimate which parameter has more influence and how it should be changed for improving hull velocity and mechanical efficiency. In this study, we evaluate many parameters such as dimensions of oar or rower's motion. And it is made clear how to change parameters which have more effects than others.