Abstract: Taking Thematic Mapper(TM) and Sattellite Positioning and Tracking(SPOT) images as the basic data, the research segments the images into identifiable image cells using a new method of segmentation after the preprocessing of terrain correction, elimination of cloud and snow, and establishment of subarea.And then, the research extracts automatically the distribution of forestlandusing the combinative method of hierarchical classification and fuzzy classification in a higher precision verification. The forestland extracted is classified in the aspect of coverage rate, and the exact distribution of high and low-coverage forestland in Three Gorges Reservoir Area is obtained by manual modification, and then, the results are made up maps and area statistics.