This paper analyzes the spectral characteristics of six major land-surfaces such as desert,forest,grassland,plain,plateau,water-body and snow-cover measured from three most sensitive 23.8,31.4 and 89.0GHz window channels of the AMSU (Advanced Microwave Sounding Unit) abroad on NOAA-16,puts forward a primary algorithm to monitor the snow-cover over Xinjiang by using the measurements from these channels,and obtains the ten-day snow-cover maps of Xinjiang from October 2001 to March 2003.The "point to point" comparison of AMSU monitoring results with ground-based observations shows that the discrimination accuracy is about 70% or higher,and the variational trend of snow-cover percentage accords generally with ground-based observations.Both of these results prove that AMSU data are useful for snow-cover monitoring and the algorithm proposed in this paper is reliable.Besides,the paper simply analyses the factors that influence the monitoring accuracy of AMSU,and then points out several problems to be resolved in the future.