Demonstrations play a major role in education process. Although many specimens are readily available, particularly in medicine and biology, demonstrations are commonly performed by showing these static specimens to medical or biological students. Interactive demonstrations can significantly impacts learning. An interactive system for visualizing 3D human organ models can fulfil this need. In this paper, we present techniques to realize such a system which can let the user select and view one or several major organ models extracted from segmented visible human dataset interactively through a simple graphical user interface. The stereoscopic views of these organ models are also achieved with this system running on a PC-based stereo-ready system. In our system, the marching cubes algorithm is used but new implementation we proposed to greatly improve both the speed and quality of surface rendering results is performed. This new implementation can generate the marching cubes cases on-the-fly within the surface extraction process of the models by considering the relationship of the vertices, borders, and surfaces of each voxel. We also describe a new method for specifying the normals for the extracted triangles without the need of physical information (such as intensity values stored in a medical computed tomography (CT) dataset) stored in the voxels. These normals will be used for lighting the extracted models later. Furthermore, a memory arrangement scheme is designed to enhance the usability of the system.