Abstract: With condensed tannin extract, molysite(FeCl3)and water glass (Na2SiO3),as raw materials, the soil amelioration agent (FSL) could serve the functions of sand-fixation, water-storage and seepoge-prevention. By means of the infrared spectrum, we found that the coitions and strength of the feature spectrum Peaks of the functional groups of FSL had changed, as compared with the those of the raw meterials. This shows that threr are coordinate actions among the compeitions.