Recently the changes in medical informatics enabled us to use medical information whenever we want and wherever we are. However, there are few information supporting systems on the web in occupational health field. So we have tried to make an occupational health information system (OHIS) based on the Internet and to provide occupational information to occupational health personnel. There were two steps for developing OHIS. First, we analyzed user's needs and existing information systems and then developed contents of our OHIS. Second, we constructed web server under the environment of Windows user, using operating system of windows NT 4.0 and web browsers of Netscape Navigator. Many users in worksites wanted information through the Internet. The contents of OHS which they wanted were information related to health education of workers, health counselling, news, and so on. The contents of OHIS which we forwarded were occupational health service, information about organization of occupational health, book references and journals, link-sites related to occupational health. In the future, this Interned-based OHIS will be an useful site offering a lot of information to occupational health personnel.