In the case of high-speed ball bearings used for supporting high-speed motors of EV(Electric Vehicle) and HEV(Hybrid Electric Vehicle), high rotational speeds cause large centrifugal forces when the bearings operate. If a large centrifugal force is applied to the retainer, it causes deformation. This causes interference between the retainer and the rolling element, thereby accelerating the heating and wear of the retainer. This is a major cause of reduced fatigue life of high-speed ball bearings. Therefore, in this paper, in order to minimize retainer deformation by centrifugal force, the material and design of the retainer were changed. The deformation by centrifugal force was measured by FEA(Finite Element Analysis) and based on this, we devised optimum design of retainer.