This paper describes a new interferometer-point-diffraction holographic interferometer. In this interferometer, a collimated beam from a He-Ne laser is divided into beams (reference and object beams) by a beam splitter; the lens to be tested is placed in the object beam with a pinhole at its focal point; another lens is placed behind the pinholt to collimate the outgoing beam and a holographic plate is placed at the position where the reference and object beams are over lapped. The pinhole is small compared with the Airy disc of the lens. After the hologram is processed, it is replaced at the original position while pinhole is taken away. The hologram is then illuminated bj both the reference and nnfiltered object beams so tlxat two interferogxams with the same distribution are formed in the object and referenoe beams behind the hologram. It is known by theoritioal analysis that this is an iBdieation of the aberration of the lens under test. The principle of this method is basically the same as thai; of a point-diffractions interferometer. But in the case of a point diffraotien interferometer, adjustment is very difficult beeau5e it uses a glass plate with a highly absorbing layer and a very small hole on it and one can not find its position easily. While if oar method is used ihere is no more adjustment diffiotilty provided that the replacement is correct. In the tranditional intexferometrio testing of a lenft, auch as Twyman-Greeii interferometer, a standard spherical mirror must be used to reflect the beam back. In addition Twyman interferograms are sensitive to vibration and temperuture. Our method, however, does not require a standard spherical mirror and can provide more stable interferograms. In addition，the same hologram can also be used in testing other lenses provided that their fecal points are exactly at the pinhole position. This method can be naed 111 testing of lenses, telescope and microscope objectives during their proceflsing or assembling. It has the merit of simple structure and easy operation.