We have two methods to realize the MR,which are called video see-through and optical see-through. In the video see-through method,real images are captured into a computer through CCD camera. The captured real images mixed with virtual images in the computer,and the mixed images are shown to observers. On the other hand,real images are mixed with virtual images optically in the optical see-through method. In this research we suggest a method of visualizing occlusion between real objects and virtual objects in optical see-through MR.