The ozone layer monitoring program of the Global Environment Laboratory at Yonsei University in Seoul, established as one of the Global Ozone Observing System($GO_3OS$) of the World Meteorological Organization(WMO), has been carried out daily by measuring total ozone and its vertical distribution using a Dobson Ozone Spectrophotometer(Beck #124) since 1984. In this paper, we review the organization and the historical background of ozone measurements in Korea, describe data acquisition and analysis systems, and briefly summarize the results from our ozone observations.