Spectral knowledge method and spectral angle mapper(SAM)are used to extract the desertification information,including flow sand,semi-fixed sand,fixed sand,and sandy plantation by taking Mu Us sandy land as a typical area and CBERS-2 as the source of data.The extracted precision of the different methods are analyzed and compared.Results show that the summarized precision of spectral knowledge method is 76.04% and SAM is 83.21%.This indicates that the extracted precision of SAM is higher than spectral knowledge method for extraction of the desertification information on CBERS images.