This paper deals with the purification efficiency of five hydrophytes growing in natural ponds and estuaries to the eutrophic ation (nitrogen and phosphorus) and heavy-metals polluted water of Dianchi Lake. Kunming.The results show that these hydrophytes can eliminate N,P and heavy metals six elements-Pb,Cd,Cr, Ni, Zn, Cu have been studied) from the water and the mud through absorption and accumulation . As the content of pollutants in water and mud is reduced, the pH value, COD value and the turbidity of t...