Hydrated calcium silicate(C S H)and hydrated calcium aluminosilicate(C A S H) with different calcium silicon ratio(nCa/nSi=0820) and aluminum silicon ratio(nAl/nSi=006) were synthesized by chemical precipitation method, and the adsorption capacity of chloride ions were studied by ion chromatography(IC) after immersion in chloride solution. The effects of calcium silicon ratio and aluminum silicon ratio on C (A) S H structure and microscopic morphology were studied by Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). The results show that the adsorption capacity of chloride are increased with the increase of the concentration of chloride solution, which conform to Freundlich adsorption model. Both calcium silicon ratio and aluminum silicon ratio affect the polymerization degree and structure of C (A) S H. Chloride adsorption capacity of C (A) S H increases first and then decreases with calcium silicon ratio. With the increase of aluminum silicon ratio, especially beyond 02, chloride adsorption capacity of C (A) S H decreases significantly.