A method of extracting several pigments in blue-green algae of Taihu Lake including Chlorophyll, Carotenoids, Phycocyain. Oscillaxanthin and Myxoxanthophyll is introduced. The pigments are measured by UV-VIS Spectrophotometry, and the method of calculationg the pigments content in lake blue-green algae is also described. Finally, the conditions of exploitation and utilization of algae pigments in the field of food industry and cosmetics industry are discussed.