Forest ecosystems provide a lot of service functions which are not only sustainable conditions for life, but also the material foundation and guarantee for human survival and socio-economic development. Therefore, these years more and more attention has been paid to forest health and health assessment has become extraordinarily important. This study is primarily based on the evaluation criteria prescribed by Continuous Forest Inventory Technique, combining with site, geography, climate conditions and so on in Liangshui nature reserve to define the evaluating indicators. In this thesis, windthrow hazarel is divided into four grades: zero, mild, moderate and severe. The data of forest resource inventory in Liangshui nature reserve in 2009 is used to calculate the accumulation of different forest compartment and species of wind fallen trees. And based on ARCGIS, windthrow hazarel geodatabase, disaster distribution, volume distribution of wind fallen trees of Liangshui nature reserve are built and mapped. Then with the combination of aspect, slope and stand density distribution, this thesis is to analyze the factors which influence the disaster grade and distribution, to propose target-oriented prevention measures and treatment strategies. The results demonstrate that in Liangshui nature reserve, forest compartments in mild disaster are the most with the total number of 21, those in moderate disaster are 4, in zero degree disaster are 4 and in severe are 2. And the area of forest compartments whose main variety of wind fallen tree is pinus koraiensis takes up over 45% of the total forest zone, the area of forest compartments whose main varieties are fir and spruce takes up approximately 40%, and the areas of forest compartments whose main varieties respectively are poplar and basswood takes up about 10% and 5%.