Abstract: In order to study the relation between the spatial frequency of interference fringes and the diffraction efficiency of transmission holograms, six transmission holograms in which the planar wave was used as reference beam and the spherical wave as object beam were taken under same situation. The diffraction efficiency was measured in the experiment and the spatial frequency was calculated. Moreover, taking the convergent spherical wave as the object beam and the planar wave as the reference beam, another four transmission holograms were made through changing the angle of the incidence light and the focus of the spherical wave, and then the diffraction efficiency was measured and the spatial frequency was calculated. The results show that the diffraction efficiency of transmission holograms made under same situation was determined by the spatial frequency but not by the reference beam or object beam, the spatial frequency changes only with the angle between the reference beam and the object beam, and that the diffraction efficiency changes according to the angle of incidence.