Abstarct: Sliding mode control theory, due to its robustness against model uncertainties and external disturbance, and simple in implementation, is one of the prospective control methodologies for nonlinear systems. in this thesis the sliding mode control strategy worked in conjunction with the field-oriented method to improve perforemance of the induction motor position controller. Stability analysis baxsed on Lyapanov theory is presented to demonstrate that the rotor position is exponentialy convergent. Simulation results are also presented to confirm the characteristics of the proposed control sheme. In general, a sliding motion can be divided into two phases: a reaching phase and a sliding phase. One of the most distinguished features of the SMC is that after reaching the sliding mode, the system has robustness to parameter uncertainties and external disturbances. However, during the reaching phase, the SMC system may be sensitive to parameter variations and external disturbances. A moving switching surface (MSS) that can remove or minimize the reaching phase has been studied by Choi et all. In this thesis, the design method of sliding mode fuzzy controller (SMFC) with a moving surface has been presented. The moving surface tuned by fuzzy logic improves the system robustness in reaching phase. The simulation results show that the SMFC is superior to PID , SMC classic and sougeno fuzzy controllers in the robustness to external disturbances.