This book introduces a non linear position controller for an IPMSM (Interior Permanent Magnet Synchronous Motor). The system model equations provide the basis for the controller which is designed using adaptive back stepping technique. By recursive manner, virtual control states of the IPMSM drive have been identified and stabilizing control laws are developed subsequently using Lyapunov stability theory. Various system uncertainties are considered in the design. Using Lyapunov¿s stability theory, it is approved that the control variables are asymptotically stable. The complete model is then simulated using MATLAB/SIMULINK software. Performance of the controller is investigated at different dynamic operations such as command position change, sudden load change.