Abstract: Colored dissolved organic matters(CDOM) directly affect the optical characteristics of sea water. As one of the fundamental parameters of inverse modeling the water organic pollution content water color remote sensing,the concentration of CDOM in the water is usually indexed by the absorption coefficeient at 440 nm wavelength,a_g(440). Therefore,in order to obtain the spatial variability of the CDOM concentration in the relevant areas and to extract other water environmental paramenters,it is essential to establish a remote sensing inverse model of a_g(440). Applying the in-site measured apparent and inherent optical properties of Zhujiang River Estuary of southern China in November 2013 and February 2014,respectively,we established a remote sensing inverse model of a_g(440) based on the HJ-1/CCD satellite. The model is then applied to Zhujiang River Estuary to obtain the spatial distribution of CDOM concentration under the clear sky between January 2012 and June 2014. The results that,(1) the in-situ measured a_g(440) in Zhujiang River Estuary varied between 0.1 and 0.3 m^-1,the value is obviously larger in the areas with high influence of land and river runoff than those with low influence of land and river runoff. It also shows some regular variation with differene sections; (2) the validation of the model by the in-situ data givers a relative error of 9%,indicating a high accuracy of the inverse model; (3) the CDOM spatial distribution data from the inverse model are in good agreement with the observation,in the whole Zhujiang River Estuary and the adjacent areas,a_g(440) varies between 0.07 and 0.31 m^-1,and the value is higher in the western part of the estuary than the eastern part.