One way to reduce power loss in metal belt CVT is to understand the coefficient of friction in the circumferential direction between the element and pulley and optimize the pulley hydraulic pressure that clamps the element. An element sensor attached with a strain gauge is used to measure the inter-element compression force that accompanies torque transmission. In addition, the element-pulley circumferential friction coefficient is calculated using the element clamping force measured with another strain gauge. From these results, we consider the power transmission behavior of the elements in the pulley.