Abstract: By analyzing the optical properties of several important ocean medium, a new method for monitoring oceanic suspended particles is proposed. The method makes use of an airborne lidar and is based on a bio-optical algorithm. The detection model on the concentration of alga Chlorophyll-a and the concentration of suspended sands based on the bio-optical algorithm were proposed. By simulation and computation, it is proved that these two detection models can monitor the concentration of alga Chlorophyll-a and the concentration of suspended sands effectively and could predict the occurrence of red tide. Baed on these two models, oceanic suspended particles monitoring can be realized.