A optical endoscope has disadvantages; giving pain and not applying to a postoperative patient. If it substitutes for a virtual endoscope, noninvasive observation can be gained. This paper describes a developed viewer, using Visual C++ 6.0 and Openlnventor2.5.2 (object-oriented 3D toolkit) library, for the manipulation of 3D anatomy object model. It is named Anatomy Viewer. The viewer is implemented under the PC environment. It can rotate, zoom in and out, and fly through anatomy models on 3D space and translate into a interested area, and then save as a TGA image file like a real endoscope. Also, as it is improved in the network, we exchange data and discuss with someone who is in the other place. This viewer is very useful to understand the anatomy structure, to diagnose, and to make a surgical plan in preoperative step. We verified its usefulness by observing a 3D bronchus model that is reconstructed with CT image slices.