A practical simulation system based on analysis of clinical surgical procedures is described. The system provides fundamental manipulation operations to simulate actual surgical activities. There is a simulated cutting operation for sectioning a bone into various arbitrary shapes, a movement operation to transport a bone block to a desired position, and a restricted-movement operation to move a bone block until it comes into contact with other bone. The system also generates a skin surface image of a postoperative patient based on a simulated plan of bone manipulation. An operational system to enable physicians handling the system to work at ease has been devised. The structure and function of the system are described, and examples of its use in simulation are given.