The computer aided surgery (CAS) is a new interdisciplinary field that emerged in the 1990s. In the field of medical images, three-dimensional reconstruction of CT images, virtual endoscopy, surgical navigation has been put into practical use and they are widely used in clinical surgery. In the field of surgical manipulation, active forceps for endoscopic surgery and surgical robots have been developed and used in clinical surgery. Recently, there has also been research into automatic recognition of surgical procedure, risk warning, and surgeon skill evaluation using artificial intelligence (AI). CAS requires further human-computer interface improvements in the following areas. In the imaging field, it is necessary to improve the human-computer interface to enable rapid and intuitive image construction. The burden of eye strain must also be solved when wearing a head mounted display. Surgical robots enable intuitive surgical operations inside the patient's body. However, burdens on human resources and required time required for preparation, tidying-up and sterilization of surgical robots remains unresolved. Also, the problem of sudden computer freezes during surgery remains unresolved. Furthermore, the interface for integrated control of various medical equipment in the operating room, such as imaging equipment and energy devices, has not yet been completed. The CAS is also expected to be applied to advanced anatomical research, medical device development, hospital management by using a large amount of surgical information in the Big Data.