The response characteristics of a CVT vehicle is investigated numerically by using a Bondgraph model. Simulation result show the continuous behavior of the engine and the speed ratio for the CVT vehicle compared to the discrete behavior of the automatic transmission. Also, the optimal operation of the CVT which is derived from the speed ratio-torque-axial force equation from the previous works. It is found that the speed ratio of CVT has to be controlled corresponding to the optimal CVT ratio that makes the engine run on the optimal operating line.