使用1999年8月30m分辨率的ETM遥感数据、DEM数据和25个典型的4^4m^2的地面实测样方统计数据、数字化了1994年的珍稀淑危植物分布图，用遥感技术西鄂尔多斯珍稀濒危植物群落进行了水平和垂直带分布规律的研究。图像处理采用遥感弱信息提取技术，识别了建群植物及其种群组合特征；并结合三维景观影像对珍稀植物种群生存生境的地貌、土壤等条件的相关性进行了分析，揭示了垂直、水平地带分异规律，建立了相关分析模型。研究结果为珍稀濒危植物动态监测和物种多样性保护提供了新的技术方法和分析决策依据。

ETM data(Aug.,1999),statistics data of 25 sampling sites with size of 4m by 4m and 1:250000 scale DEM data.and digitized 1 to 100000 scale distribution map of endangered rare plants are used to study the vertical and horizontal didtribution patterns.Endangered rare plants group information was extractrd by using Masking Princioal component transformation and Hue adjust(MPH)technique.And then the feature imagery was merged with DEM data to produce a virtual reality 3-D imagery to see the differences of rare plant in relation to topographical and soil enxiroment.The soil type is affected rare plants in West Ordos Plateau,mainly Tetraena mongolica,Helianthernum soongolicum,Reaumuria trigyna,Reaumuria soongorica,Potaninia mongolica,Ammopiptanthus mongolicus and they are evolved from Tertiary,are for a long time regarded as enxironment change dianostic indicators.They also have very precious value to study environmental evolution,plant diversity and geography in global scale.These plants have also played a very important role in maintaining ecosysetem in terms of preventing desertification.The vegetation spectral featuer ranging from 0.63 to 1.1 μm is called reflectance “shoulder”,which is the spectral character for NDVI,BIOMASS and NPP calculations,In the study we used TM and ETM blue bands(0.63-0.69μm)and near infrared band4(0.775-0.90μm).To differebtuate soectral features of rare plant groups the MPH technique was used.The technique was implemented in two steps.Masking,and Principal component transformation.Firstly,water bodies and some alluvium were masked out from ETM1,2,3,4,7 bands,which could reduce the variance features for next step processing.Principal component transformation algorithm had the function that can compress the common features into first component.In order to get rid of terrain illumination(mainly BRDF/ALBRDO)from all imported hands,we used the PCA compress function to reduce terrain illumination.After Principal Component Analysis the first component contained most of common BRDF/ALBEDO information.Three MPH resultants,MPH 2,MPH 3and MPH 4 were selected and combined to make a color composite.The method emploved in the study can be widely used as monitorying tool for the future decision making in protection of the endangered rare plants.