The present invention provides a bearing with retainer, which comprises: an inner ring configured with a rolling groove on the outer periphery; an outer ring disposed on the outer side of the inner ring and configured with a rolling slot with respect to the rolling groove; a retainer, which is circular and disposed between the inner ring and the outer ring and is configured with a plurality of spacers arranged with intervals, wherein a retaining portion is defined between every two spacers and the surface of the retainer is kept with a distance to the inner ring and the outer ring; a plurality of rolling bodies disposed on the plurality of retaining portions and contacted with the rolling groove and the rolling slot. The spacer has two retaining surfaces for retaining the rolling body, and the retaining surface has a linear segment. The bearing can be deformed with an elliptical wheel and can keep the rolling body with a displacement defined by the linear segment in the retaining portion for moving up and down , and thus to keep the surface of the retainer having a distance with the inner ring and the outer ring without frictional interference with the inner ring or the outer ring.