Eutrophication issue of water body has been increasingly troubling many environmentalists and the algae blooming has also been decreasing the water quality.La-modified bentonite is a new way,which has been developed for soluble phosphorus removal from water body.From the in-situ demonstration trial near Lake Dianchi,located in Kunming,this La-modified bentonite has been approved in effectively removing soluble phosphorus from the eutrophical water body,like the Dianchi water.It could remove soluble phosphorus (SP) in 95.4％ and total phosphorus (TP) in 84.3％ from the lake Dianchi water.With the treatment by La modified bentonite,the water body also had low concentrations of ammonia,nitrate,CODr etc,as well as the limited concentrations of both SP and TP.However,the water transparency of the treated water body was transferred to a high level,and the water body was also turned from the beginning algae blooming to the following various aquatic plants growing,as the healthy water quality indicators.In a word,through the La-modified bentonite treatment,La-modified bentonite could effective remove soluble phosphorus from water body,and with the co-efficiency,it could also hold good control in both other pollutants,like ammonia,nitratc,CODcr etc and the algae blooming for eventually purifying the eutrophical water body.