Automatic Water Quality Monitoring System(AWQMS) was established in Fe Semo I which runs three times every week from Inchon to Cheju. The system includes measuring equipments for water temperature, salinity, pH, dissolved oxygen(DO), fluorescence and turbidity. In addition, the time and location of observant were recorded with a Global Position System (GPS), and nutrients and suspend solids (SS) were simultaneously collected and analyzed. In order to test the accuracies of AWQMS, reference measuring instruments was also applied and both results were compared. Various examinations were subject instrumental and experimental errors. In case of temperature and salinity, all the instruments precisely and accurate measured the parameters, regardless of instruments, time, and location. Although DO, fluorescence, and turbidity data measured showed regional difference, there were various data following differences in specificity of instrument and degree calibration. Few difference were also coming from the differences in suppliment a distribution of sea water. The results of nutrients and SS measured semiautomatically in laboratory showed regional charateristics.