Abstract: DaLi lake water type is CINa ,high contents of the top of sodium ions and potassium ions in water, content of calcium ions with weak antagonism effect ,make up in the water for lining in one of the aquatic animal have strong toxicity with high pH and high non-ammonia water in DaLi lake, which has strong toxicity to aquatic animal. These two factors are the main reasons leading to less aquatic animal species in lake. Cyanobacteria dominated in DaLi lake plankton, inorganic carbon concentrating mechanism in cyanobacteria can cause water PH value increased significantly in cyanobacterial photosynthesis process, cause outbreaks of fish died, the abundant biomass planktonic animal and benthic animal in the amount of 1.365mg/L and 9.91 mg/L, hut economic fish only carp and Leuciscus waleckii. Feed resources are not fully utilized. It is urgent to find special economic fish stocking can make full use of food resources, and adapt to lake water quality.