Saemangeum tideland reclamation project in Korea has been started in November 1991 to construct 33km long sea dikes, 28,300 ha of land and 11,800 ha of freshwater lake. The end of 2004 completed 85% of the planed construction works for sea dikes and sluice gates. Multidisciplinary survey program on the oceanic environment in the Saemangeum area has been started in early 2002. In the survey program, physical, chemical, biological and geological oceanographic survey and in situ monitoring were included. We established an integrated data management system of the multidisciplinary survey program. The integrated data management system was designed to present its service to end users through internet web site. The data service system was based on a metadata management system. The metadata management system provides information of observation according to user defined query condition such as observation items and time, etc. End users could get the final observation data were linked with the metadata as a table and/or graph. And real-time observation data were another major part to compose the data management system. In situ observation data for oceanographic and atmospheric parameters from 3 buoys and a tower transmitted to data server and processed results were also displayed graphically as well as numerically on the data service web site.