Large area of turbid water body and aerosol with high absorption are the main characters of the offshore coast of our country. A new algorithm is developed to retrieve aerosol optical characteristic over coast waters. Based on several look up tables (LUT) and MODIS image of the clear water with ground surface in the clear sky, the model I uses the interpolation method to retrieve the aerosol optical characteristic over the turbid waters. Preliminary validation results comparing with AERONET data in Dongshan island show that the algorithm has good accuracy and promising potential. By using the algorithm, the preliminary retrieval of aerosols are carried out for MODIS data of ocean surface in Bohai bay area. The new algorithms would be useful in studying the atmospheric correction models of HY and FY satellites. And it can directly use CMODIS data of FY-3 to retrieve accurately aerosol optical characteristic and water color of coast zone.