Abstract: In order to investigate the absorption performance of calcium silicate to total phosphorus in the eutrophic lake water，a series of experiments were carried out in summer and winter respectively.The mass concentrations of total phosphorus in water samples were 0.19 mg/L and 0.10 mg/L in summer and winter respectively.The results of experiments showed that the removal rates of total phosphorus in summer and winter could reach 89.26% and 76.54% respectively when pH was 6， the dosage of calcium silicate was 0.8 g per 100 mL water sample，and the oscillating time was 60 min.The absorption isotherm fitted to Langmuir and Freundlich isotherm formulas，with the maximum absorption capacity of 5.32 mg/g. 

Key words: calcium silicate, eutrophic, absorption, total phosphorus