The main chlorides that pollute soil are NaCl, KCl, MgCl2and CaCl2, who will change the physicochemical properties of soil. It takes Jiuzhoutai loess as the object, using methylene blue method and ethylene glycol monoethyl ether method to determinate the specific surface area of loess, which was immersed by chloride with different concentrations and cations to analyze the influence of chloride contamination, respectively. The specific surface area decrease with the increase of chloride concentration, while has the negative correlation with the affinity of cations to clay which immersed by different cations. Different absorbents that have lead to the difference of test results, and the results of ethylene glycol monoethyl ether method are always bigger than methylene blue method.