| The Nujiang River is one of the five international rivers in Southwest China. The Nujiang river basin possesses the abundant species resources, complex geographical distribution and diversiform endemic groups, so the Nujiang river basin is the important region of biodiversity and ecological landscape protection in the world.In this study,we used 2006 TM image and GPS as remote sensing date for present vegetation mapping of the Nujiang River Basin of Yunnan to develop a classification system. We extracted MODIS-NDVI seasonal variation informations of each vegetation types based on vegetation present map and GPS information, and then analyzed NDVI seasonal variation of each vegetation types. The vegetation coverage status derived from retrieval model of vegetation index and vegetation coverage based on ERDAS9.1, then we used Arcview 3.3's spatial analysis model to analyze distribution characteristics of different slopes, aspects, elevation and erision classes for every vegetation coverage classes, the results revealed vegetation spatial distribution of study area .Mail results were as follows:After extracting 19 different kinds of natural vegetation and plantation forest from MODIS NDVI, every vegetation types showed growth and recession periods with its own characteristics,the results reflected natural growth rhythm. In this paper, used the extracted NDVI information to analyze NDVI seasonal variation for each vegetation types .The five indexes are annual accumulated NDVI value (NDVIja) , average NDVI value (NDVIjm) , maximum monthly NDVI value (NDVImax) , minimum monthly NDVI value (NDVImin) , and annual range NDVI value (NDVIjr). The results showed that monsoon rainforest has the maximum value of NDVIja, NDVIjm and NDVImin, the value is 7.913, 0.659 and 0.625 respectively. Monsoon rainforest and monsoon evergreen broad-leaf forest have the maximum value of NDVImax .Subalpine meadow has the minimum value of NDVIja, NDVIjm, NDVImax and NDVImin, the value are 3.069, 0.256, 0.156 and 0.360 respectively. Dry– temperate valley scrub/shrub-grasslands has the maximum value of NDVIjr, the value is 0.389. Warm-hot coniferous forest has the minimum value of NDVIjr, the value is 0.032.The vegetation coverage was classified four classes (no or very low vegetation covered area, low vegetation covered area, middle vegetation covered area and high vegetation covered area). Then the vegetation coverage superimposed with different topographical factors and soil erosion classes to analyze the distribution characteristics, the distribution characteristics were as follows: In aspect of slope , the no vegetation or very low covered area, low vegetation covered area, middle vegetation covered area and high vegetation covered area mainly distributes in the 15~35°, 0~8°and 15~35°, 0~8°and 15~25°, 15~35°respectively, compared with total area of each vegetation covered area, the percent are 60.19%,75.11%,58.65% and 55.93%. In aspect of aspect, the no or very low vegetation covered area and low vegetation covered area mainly distribute in the west, southwest, northwest and north slope, north, west, southwest slope.The middle vegetation area mainly distributes in the north slope, but the high vegetation covered area distributes same percentage for each slopes. In aspect of elevation, the no or very low vegetation covered area mainly distributes in the region of 2000-2500 meters and more than 3000 meters, the low vegetation covered area mainly distributes in the region of 1500~2500 meters and more than 3500 meters, middle vegetation covered area mainly distributes in the region of 1000~2000 meters, the percent is 60.90%, the high vegetation mainly distributes in the region of 1000~3000 meters. In aspect of the soil erosion, the area of each vegetation covered mainly distribute in the low erosion class (mired erosion , mild erosion, moderate erosion),the percent is 78.96%, 75.00%, 62.23% and 66.46% of each vegetation covered classes, the results showed that middle and high vegetation covered area can control soil erosion.
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