Chloride binding in cement can reduce the risk of steel corrosion of concrete. The influence of chloride concentration, composition of corrosion solution, temperature on chloride binding in monosulfoaluminate hydrate was investigated by analytical methods including X ray diffraction. The results show that the binding relationships between free and bound chloride can be described by the Freundlich isotherm. Chloride binding of monosulfoaluminate hydrate is attributed to the formation of Friedels salt through ions exchange of chloride ions and sulfate ions. Calcium ions of corrosion solution can increase chloride binding capacity in monosulfoaluminate hydrate comparing with sodium ions. The chloride binding ability in monosulfoaluminate hydrate reduces with rise of temperature.