Design of electric power steering control system by using μ synthesis was presented, the modeling uncertainties and the external disturbances were considered during the designing of EPS control system. Based on the requirement of electric power steering performance and system specifications, the EPS control system architecture and the weighting functions were selected. The μ controller of EPS has been worked out by using μ control toolboxes in Matlab. Simulations and the calculated μ results showed that the designed μ controller performed satisfactorily and inherited the imposed robustness and performance sections.