Abstract: Based on comprehensive filed survey and image analysis,we developed a classification system for Jin Shajiang River Basin (Yunnan part),in which the basic units was reference to the subtype in Yunnan Vegetation.There were 5 types of vegetation totally:broad-leaved forest,coniferous forest,shrubs and grass,meadow and plantation.We used Alos images in 2010 as data source to interpret the vegetation on the studied areas by human-computer interaction,then used MODIS NDVI data to extract various types of information on seasonal variation of MODIS NDVI.So we constructed 5 indexes of seasonal variation of vegetation spectral characteristics to analysis vegetation variation.The results showed that:①The broad-leaved forest was more than other vegetations ,followed by coniferous forest,shrubs and grasses and plantation,meadow was the minimum on NDVIjmax.The broad-leaved forest was more than other vegetations,followed by plantation,brush and grass and coniferous forest,meadow was minimum on NDVIjmin;②The hedges and irrigation grass was higher levels,followed by coniferous forest,broad-leaved forest and meadow,plantation was minimum on NDVIjr;③The broad-leaved forest as more than other vegetations,followed by coniferous forest,shrubs and grasses and filling plantation,meadow was minimal on NDVIja;④ The broad-leaved forest was higher levels,followed by coniferous forest,shrubs and plantation,and meadow was minimal on NDVIjm.