Induction motors are the most preferred motors in industry because of their simple but robust structure. Optimization methods are widely used in design of electric motors. Moreover there are many literature surveys on application of optimization methods to electric motor. This study is focused on optimization techniques in design of induction motors to help researchers to gain background knowledge of studies. In this paper firstly electric motors types and motor efficiency classification standards are introduced. Secondly, brief explanation on design of induction motors has been given. And lastly the contributions of various researchers to improve the performance of induction motor have been studied. It also examines various techniques and algorithms to design electric motors.