Gracilaria lemaneiformis (Bory)Webervan Bosse is an economically important red seaweed that is cultivated on a large scale in China due to the quantity and quality of agar in its cell walls.This alga is also considered an excellent species for alleviating coastal eutrophication,which has become ever more serious in China.To aim at such a function of bioremediation,in this study,the characteristics of inorganic phosphorus(Pi)uptake in G.lemaneiformis were investigated.Thalli were incubated in artificial seawater with f/2 enrichment and different Pi concentrations under different conditions of temperature(15,23,31 ℃),irradiance levels［0,30,200 μmol photons/(m²·s)］and nitrate concentrations(0,30,200 μmol/L),and the uptake dynamics of Pi were determined.The results showed that the uptake dynamic curve of Pi was always accordant with Michaelis-Menten equation under various conditions.The maximal uptake rate of Pi increased with the enhancements of temperature and nitrate concentration.However,the ratio of maximal uptake rate and halfsaturation constant(V_m/K_s),which represented the efficiency of Pi uptake,was the highest at the lowest temperature(15 ℃)and the level of nitrate concentration close to natural seawater(30 μmol/L).Both the maximal uptake rate and efficiency were higher at lower irradiance level［30 μmol photons/(m²·s)］than at higher level［200 μmol photons/(m²·s)］or dark［0 μmol photons/(m²·s)］.It is concluded that environmental factors such as temperature,irradiance level and nitrate concentration,could significanty affect the Pi uptake in G.lemaneiformis,and the mechanisms should be further studied in detail.