Abstract: Oasis and rural settlements are the core of human production, living and ecology in the arid regions of Northwest China. Exploring the relationship between oasis and settlements is important for new urbanization construction and rural revitalization in arid regions. Therefore, the paper takes the Hexi Corridor as a research area, which is located in Gansu Province, China. In this paper, the data of settlements and oases is derived from the visual interpretation of Google earth, and uses the GIS spatial analysis, landscape pattern index and hierarchical clustering method to systematically analyze the spatial scale, morphological structure and type characteristics of the urban and rural settlements in the Hexi Corridor in 2016.Under the background of ecological environment, the oasis breeding index of settlements in the arid area was first proposed to analyze the oasis breeding degree. The results are shown as follows: (1) The scale difference of rural and urban settlements is obvious, showing the larger the pattern scale of distribution is, the smaller the proportion of patches is, and high-density distribution of small patches and low-density large-scale distribution of different characteristics, and the scale of residential land is generally small, with an average size of only 0.05 km², and the density and agglomeration of settlements are both declining with the core of the city, and Hot spot detection found that the east of Shandan County is the hot spot region of the spatial distribution of settlements. (2) The analysis of the morphological structure of settlements shows that the connectivity and stability of rural settlements gradually weaken from east to west, and the area differentiation of settlements is gradually reduced from the “center-edge” of the city, the mean shape index and mean patch fractal dimension of the settlements in Guazhou County, Yumen City and Jinta County are highly coupled, and the patch shape is complex, the natural distribution is strong. (3) The oasis ecological environment in Jiayuguan City is the most vulnerable, the urban and rural development is greatly restricted. However, the oasis hinterland of Liangzhou District, Minqin County and Ganzhou District has a wide space, which is conducive to urban and rural development.

Key words: settlement, spatial scale, morphological structure, oasis breeding index, Hexi Corridor