Basing on the conventional Kellner eyepiece, four hybrid refractive|diffractive eyepieces with different locations of the diffractive surface are designed. Only a kind of glass K 9 is used in the optical systems. The optical performance of the hybrid eyepieces are studied and compared with the Kellner eyepiece. It has been shown that the hybrid eyepieces take the advantages of improving aberrations, such as astigmatic, lateral color, transverse aberration, longitudinal aberration and chromatic focal shift, as compared with the Kellner eyepiece, and a satisfactory distortion can be obtained if a suitable location of the diffractive surface is chosen. The size and the weight is greatly reduced due to the introducing of diffractive surface.