The automatic classification of land use was carried out on the basis of Landsat ETM+ (TM) sensed data of two different periods in this paper. The extraction of land use information by different change detecting techniques was discussed. The results of the test region showed that the spectral variation method based on fusion data is the best. In the fusion image, the least width of the new linear land use type is 9.8m, and the least area of the new plane type is about 1000m2. The fusing image can be used as guiding data in land use dynamic monitoring.