The purpose of this research is finding out the optimal wavelength band for estimating inland water qualities with high precision using water surface spectral reflectance ratio for use in ocean color remote sensing. When the water surface spectral reflectance is observed in an inland water, it is generally recognized that an absorption band of light is in a red wavelength band (660-680nm), and a fluorescence radiation band is in a longer wavelength band than red band. The proposed optimal wavelengths for the estimation of the inland water qualities are different among the observation points in the range of red and near infrared. This paper showed the difference of water surface reflectance ratio by two wavelengths of the absorption and the fluorescence radiation band has a correlation with chlorophyll-a concentration. The optimal wavelengths which are required for the estimation of chlorophyll-a concentration and turbidity were found out using correlation analysis.