For the improvement in a power transmission performance of dry hybrid belt for CVT, it is very important to raise the conversion ratio from pulley thrust to belt tension. In order to do that, it is necessary to show the factors affecting the conversion ratio and to clarify the mechanism why the difference between the ratios arises. In this paper, focusing on some structural factors which are experimentally observed or supposed to affect the ratio, the mechanism is discussed by means of power transmission analysis using FEM.