Based on five filed cruises in 2011 from Taihu Lake, the effect of particulate organic carbon (POC) assembles on remote sensing reflectance of water was performed to develop a new POC estimation algorithm for eutrophic inland waters. The optical model was used with monthly MERIS data to assess the temporal and spatial variability of surface POC reservoirs in Taihu Lake. The results demonstrated that the particulate organisms highly controlled the remote sensing reflectance of water in the range of 560～709 nm in this lake. The approaches from ocean color did not provide good estimates of POC concentrations in Taihu Lake, a more optically complex water dominated by inorganic detritus. By investigating the optical properties of the eutrophic water, we found that POC was distinctly correlated to the remote sensing reflectance ratio (Rrs(620)/Rrs(709)) with high R2=0.75 and low RMSE=33.27%, the correlation of which provided a good estimate of POC concentrations in Taihu Lake.