| As a rare, endangered and endemic species to China, Przewalski's gazelle (Procapra przewalskii) once distributed in Inner Mongolia, Gansu, Ningxia and Qinghai. The gazelles are now only living around the Qinghai Lake. In this dissertation, distribution and number of Przewalski's gazelle's population, vegetation classification, landscape pattern and dynamics of the gazelle's habitats were studied based on field investigation. And then, assessment of the gazelle's habitats was conducted using geographical information system and the suggestions for conserving Przewalski's gazelle's population and habitats were summarized. The conclusions are as follows:1) Four sub-populations were newly found and the number of the gazelle's population increased. It was thought that the gazelles were only distributed in Niaodao, Yuanzhe and Hudong-Ketu in the west and northeast of the Qinghai Lake. In this study, four sub-populations were newly found in Shengge in Tianjun, Talexuanguo, Ha'ergai River-Qinghaihu Township and Qiejitan respectively. The total number of the gazelle's population is up to about 600. Due to geographical obstruct, there hardly is any chance for gene exchange among some sub-populations, and because of human disturbances it seems very difficult to exchange gene among the other sub-populations.2) Vegetation in Hudong-Ketu was classified into four vegetation types by using TWINSPAN program, namely Carex meadow comm., Achnatherum comm., Poa and Artemisia comm. and lake-shore sandland grassland comm., with a biomass of edible plants of 311.12 g/m2, 93.01 g/m2, 225.40 g/m2, 43.35 g/m2 respectively. Because with more abundant edible plants have mostly been fenced, it is difficult for the gazelles to enter the fences for feeding and they generally feed within with lower edible plants. 3) Based on white and black aerial photos taken in 1963 and TM imageries of 2000, the author worked on landscape classification and cartography in Hudong-Ketu area and completed maps of landscape types of 1963 and 2000. The results of landscape pattern and dynamics analysis show that, since 1960s the Hudong-Ketu landscape has experienced big changes, for instance, the area of farmland-residential patches increased obviously, shifting sandland spread by 17.33% and the landscape trends to homogeneity. 4) The main factors that influence habitat quality of the gazelles are edible plant richness, slope, shield area and human activities, etc. The assessment results show that the habitats livable for the gazelles account for 90.4% of the study area without human disturbance; while under impacts from human activities, the suitable habitats disappeared and the gazelles can but occupy the less suitable habitats—transitional zone between sandland and grassland, the livable habitats for the gazelles decreased 63.6%.5) At present, Przewalski's gazelle are confronted with habitat isolation, habitat fragmentation, becoming wolves' prey and food shortage in winter. This study suggests establishingnew reserves or adjusting the existing planning of nature reserves in this region, removing fences in some key areas, controlling wolves' population, increasing feeding by human in winter, building base for breeding, and strengthening scientific research on this species, in order to conserve the gazelles' habitats.
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