Abstract: Polymeric aluminum sulfate (PAS) is an inorganic macromolecular coagulant which has been reseached and developed with polymeric aluminum choloride (PAC) synchronously.PAC has become the world′s leading water treatment coagulants,while,PAS has not been able to successfully put into industrial production and application.Main reason lies in PAS′s chemical stability,production,and use cost.As Shenzhen Zhongrun Water Industry Technology Development Co.,Ltd.changed the process flow and developed a new additive for PAS,the stability period of liquid PAS has exceeded one year,and the production cost is just as the same as aluminium sulfate(AS),but the use cost is lower than the other inorga-nic coagulants.Therefore,PAS has already possessed the broad prospects for industrialisation and application. 