Person-to-person transmission of Norwalk virus(NV) is important factor for outbreaks in nursing homes in addition to foodborne and waterbone transmission. NV spread easily among residents and staffs through the care process and highly infectious contamination generated by vomitus and feces remains on the environmental surface. As a result, the outbreak continues for long period(a few weeks) compared with foodborne gastroenteritis outbreak in restaurant. For prevention and control of NV outbreak in nursing homes, it is necessary suitable efforts to break off the transmission routes; frequent handwashing, adequate measures against infectious materials such as stool and vomitus, cleaning with an appropriate germicidal product, and to minimize any mingling of residents and visitors until termination of the outbreak.