This paper deals with controlling DC-DC boost converter by average sliding controller (ASC) cascaded with PI voltage controller. In the study after modeling of circuit configuration, the cascaded PI-ASC controller is applied to the DC-DC Boost converter. The output value of PI voltage controller is used as a reference current value for ASC which is used for current controller. The topology is modeled and simulated in MATLAB/Simulink program under variable load. Then the simulation results of the PI-ASC controller are compared to that of PI-PI controller.