Recently, according to Eco-technology accelerating, new types of the traction motor with the high efficiency and power are demanded. This paper presents that the Hairpin winding is applied to a design of the electric vehicle traction motor for the high efficiency and power density. Generally, the winding method using the toroidal coil has the restriction which exist the unnecessary space between coils. But the winding method using the Hairpin reduces the gap between coils, whereupon the space factor is higher than others. However, because of using the full pitch winding and wave winding, this method has the disadvantages of increasing the THD of back electromotive force and torque ripple. Thus, to minimize the THD and torque ripple, the full factorial method, Response surface method and the step skew to the rotor are used. The paper presents the motor having the Hairpin winding for the high space factor, and the analysis result by using RSM, the method shows the reduced space harmonics.