Abstract: In order to study  the growth characteristics and accumulation ability to N and P of water hyacinth in different water areas of the Dianchi Lake,Eichhornia crassipes were planted by fence facilities with the initial planting amount of 3kg·m^-2 in six experimental points in Caohai and Waihai of the Dianchi Lake.Water quality of the experimental water area, growth characteristics of E.crassipes and plant total nitrogen content and total phosphorus content were monitored every two weeks.The results showed that since the concentrations of N and P in the Caohai water were higher than other experimental water area, the average biomass growth rate of E.crassipes was 542g·m^-2·d^-1 with the accumulated biomass of 85.37kg·m^-2 throughout the year,plant total nitrogen content of 32.9g·kg^-1 and total phosphorus content of 8.24g·kg^-1. Since the concentrations of N and P in Baishan bay of  Waihai water were lower, the average biomass growth rate of E.crassipes was 150 g·m^-2·d^-1 with the accumulated biomass of 27.00 kg·m^-2 throughout the year,plant total nitrogen content of 15.0g·kg^-1 and total phosphorus content of 6.49g·kg^-1 . In brief, pH, the concentrations of N and P in water and wind wave are the main factors affecting the growth of  waterE.crassipes .

Key words: E.crassipes, Dianchi Lake, biomass growth rate, nitrogen, phosphorus