The results from the joint experiment of remote sensing on the Bohai Bay indicated that there exists a statistical quantitative relationships between the reflectance of the spectral blue region on aerial color infrared photographs and chlorophyll-a in the Bohai Bay Correlative coefficient between the reflectance at 500 nm and chlorophyll-a concentration is-0.913. After analyzing the experimental data, regression equation can be shown. as follow : Chlorophyll-a (mg/m3)=6.33-8.47 R500. The Haihe River water with its high chlorophyll-a content appears deep blue and the Ji-yun River water with its high suspended sediments is blue green on the color infrared photographs. So that it is easy to discriminate the two waterbodies with different water quality on the images.