Abstract: Based on the "ZY 3" satellite image data,this paper extracted vegetation information of Two-River Source Nature Reserve which has complex terrain and diverse vegetation types by using the pixel classification and object classification methods. With the object classification method,the altitude information(DEM) was then introduced to further analyze the area ratio and spatial distribution pattern of different vegetation types. The results show as follows:(1) the classification accuracy of object classification reached up to 93.11%,which was significantly higher than that of the pixel classification in the varied vegetation types of alpine region;(2) according to the classification results,the study area was mainly characterized by mixed broadleaf-conifer forest and meadow,accounting for 26.37% and 22.87% of the total area,respectively;the area ratio of shrub,grassland,water body and alpine vegetation were 15.2%,10.98%,8.23% and 5.57%,respectively;(3) mixed broadleaf-conifer forest mainly distributed in shady slope or mountain valley,while meadow in plain,lowland floodplain,forest and alp,showing no significant zonality;grassland run in strips and patches across the whole area,shrub distributed in bulk inside the grassland;alpine vegetation scattered in patches in the alpine screes,gravel slopes and alpine peneplain;(4) there were five complete natural vertical bands,from high to low,they were ranked as:grassland, shrub,mixed broadleaf-conifer forest,meadow,alpine vegetation and glacier snow. The above results reveal that there are 7 kinds of object information in this area,the horizontal and vertical distribution patterns of vegetation are similar to that in the south slope of Altay Mountains,but have its own characteristics due to the influence of micro topography and local micro climate. In the later research,if season information was to be introduced into classification,not only the classification accuracy of complex terrain vegetation will be improved,but also the secondary vegetation types in hierarchical classification can be studied,it can also provide technical support for Altai Mountains natural vegetation research and protection.

Key words: Two-River Source Nature Reserve, information extraction, remote sensing of vegetation classification, spatial distribution of vegetation