Abstarct: In this thesis, the control of nonlinear non-affine systems is studied. These systems have more complex equations than other nonlinear systems due to nonlinear relationship of inputs in the dynamical equations of the system, and a general method for controlling this type of systems has not yet been proposed. The use of pulse width modulation as a tool to convert a non-affine to affine system and the design of a controller baxsed on the Filippov technique are the main idea of this thesis. The non-affine conversion system using this method is associated with uncertainty, which is considered in the controller design. Since the input applied to the system in this method is considered as two fixed values, a new idea for controlling non-affine systems is proposed that can also be applied for affine systems with input limitation. The upper bound of uncertainty is also estimated in the controller design. The stability of the proposed control methods is performed using the Lyapunov theory and its results are simulated in MATLAB software.