Abstract: There are many concepts on oasis and differences in the study of it. In this paper，oasis is determined as a natural synthesis; it is formed，affected and derived commonly by multiple factors，such as climatic，topographic，hydrologic，soil，vegetation，animal factors and human activities. It takes place in an arid desert background，its environment is beneficial to life living，and its productivity is much higher than that of surrounding desert. As an actual method and result: using the temporal and spatial data of terrain，precipitation，vegetation，grassland，soil and landuse in 2010 of Xinjiang，supported with GIS，the boundary lines of arid deserts and oases in Xinjiang are obtained. The oasis area is about 9.63% of the whole area of Xinjiang，the landuse types of oases in Xinjiang own woodland，high and middle cover degree grassland，water area except snowcover and glaciers，swamp，resident and construction area，irrigation farmland. This oasis contains natural oasis and artificial oasis，and the two parts are almost half and half. The paper gives a new concept on oasis with the physical geography and artificial factors，and gives a method of synthetic judgment to get the arid background and oasis in Xinjiang; this result can reflect the present situation about landuse structure of oases in Xinjiang. And this result is in a dynamic change. With a multitude of temporal and spatial data updating and new investigation carrying out，its precision will be improved.

Key words: arid desert, oasis, GIS, Xinjiang