Abstract: An amendatory algorithm is developed to correct the atmospheric effects for coastal waters by combining the Gordon’s atmospheric correction algorithm and the Arnone’s re-search results.Coastal waters can have significant reflectance in the 748 nm and 869 nm channels of MODIS or other instruments.The new method separates the water leaving radi-ance from the aerosol path radiance in these two channels by solving a set of simple algebraic equations,and the derived aerosol path radiance is then extrapolated to the expected chan-nels.The result demostrates that this atmospheric correction algorithm can achieve very high accuracy,and can be used to the areas where no caseⅠwaters existed or caseⅠwaters just covered by clouds.