Because compulsory investigation may arrogate fundamental human right gravely, criminal procedure law regulates requirement and process to it. Investigation agency and court have to keep to such due process. Especially when drunken driving suspect is fallen into unconsciousness, blood of suspect is important proof. Criminal investigation agency want to extract and use as evidence. In this case, investigation agency need warrant for her search and seizure without her consent. However according to Korean Supreme Court(98do968, 1999), criminal investigation can ask doctor and nurse to extract unconscious suspect’s blood and use as a evidence on the premise of doctor or nurse’s consent, not suspect running article 218 of criminal procedure law. However, this decision soil ideal of warrant principle. In warrant principle, investigation agency present the warrant to deprived person of the benefit and protection of the law because of such investigation. In order to protect suspect’s information, article 218 of criminal procedure law have to be interpreted strictly. Ultimately, legislation for extracting and using suspect’s blood as a criminal evidence is needed.