Three-dimensional (3D) structure of the bronchopulmonary segments should be understood for accurate diagnosis and treatment of lung diseases. Two-dimensional (2D) tools (e.g. anatomy books) or traditional 3D tools (e.g. plastic models) are not sufficient for understanding 3D structure of the bronchopulmonary segments. The lung of a cadaver may not always be available for dissection, when it is needed. To overcome this problem, virtual dissection programs of the lung have been made. However, most programs include either 2D images that do not permit free dissection or radiographs that do not reveal true color and have limited resolution, and cannot represent 3D structure of the bronchopulmonary segments. Moreover, it is necessary to make a virtual dissection program of each race and ethnic group. Thus, we attempted to make a 3D image and virtual dissection program of the lung using a Korean cadaver in order to help medical students and doctors better understand 3D structure of the bronchopulmonary segments. One pair of lungs was extracted from a Korean male cadaver. Dye with specific color was injected into each segmental bronchus to distinguish bronchopulmonary segments. The lungs were embedded with gelatin solution, and serially-sectioned with 1 mm- thickness using a meat slicer. Sectioned specimens from each lung were inputted into the computer using a scanner (300 X 400 resolution, true color). 2D images of the lungs were aligned on the alignment program which was composed using IDL language. In 2D images, the bronchopulmonary segments were manually segmented by help of dye. 3D images of the bronchopulmonary segments were reconstructed through the volume-based rendering of 2D images. With 3D images as the main features, the virtual dissection program of the bronchopulmonary segments was composed using IDL language. Various virtual dissection functions, such as sectioning a lung at free angles to show its plane, identifying the bronchopulmonary segments represented in the sectioned plane, and rotating the selected bronchopulmonary segments at free angles, were established. This virtual dissection program of the bronchopulmonary segments is helpful in better understanding 3D location and shape of the bronchopulmonary segments; it is expected to be used through CD-title or Internet as an educational tool for medical students and doctors.