Noninvasive virtual endoscopy is a new method of diagnosis using computer processing of 3-D image data sets (such as CT or MRI scans). Conventionally, two methods have been used in virtual endoscopy. One is 3-D surface rendering method. 3-D surface of human organs can be explored in real time by using this method, but surface rendering algorithm has disadvantages such as the low quality of visualized image and the loss of the volume data. The other is perspective volume rendering method. The power of perspective volume rendering is that the intrinsic 3-D richness of the volume data is preserved. However, there are the difficulty in planning flight-path and the disability of real time flight for a computationally intense procedure. This paper presents virtual endoscopy using both surface and perspective volume rendering. By combining each merits of two methods, a user can not only process virtual endoscopy interactively in real time but also view lossless and high-resolution image using the flight path defined by surface rendering. As a result, the use of common fly-paths removes the burden to define a flight-path in conventional perspective rendering method. Also 3-D object is explored in real time and viewed as lossless and detail cine sequences.