Abstract: In this study, water-soluble glass based on an Na2O-ZnO-SiO2 system was fabricated and its properties related to inhibition of marine biological pollution were analyzed as a function of the amount of Na2O in the glass. An ion dissolution test in seawater was performed for 1-14 days for glass containing 20~35 mol% ZnO. From the results of the ICP analysis, it was confirmed that the amount of dissolved ions was closely related to the composition of the water-soluble glass and the immersion time in seawater. The Na ions dissolved to 3 order ppm while the Si and Zn ions were dissolved to just a few ppm. B. thuringiensis strain, a gram-positive bacterium was used to measure the bactericidal ability of water-soluble glass. It was found that the bactericidal ability of the glass increased with the amount of Zn ions dissolved and the immersion time in seawater. In conclusion, water-soluble glass based on a Na2O-ZnO-SiO2 system could be applied to suppress marine bio-fouling pollution.