Abstract: Abstract:The ecological environment in lakes has been changed due to inflow of large amount of organic pollutants,as a re sult,the food chain in ecological system has been damaged,forming the dominant species of algae and producing eutrophication.This article describes a research method to partially change again the ecological environment in small scale by reproducing large amount of rotifers to eat algae,so as to revive the ecological system.After a partial small ecological system has been revived,the equipment can be moved to another area for revival.In the way,the eutrophication in lakes can be finally harnessed.