Abstract: China has numerous mountainous areas, which accommodate a large number of villages. Solving the rural problems in mountainous areas is of great significance to the construction of a well-off society and to the overall development of China. In this paper, based on the landscape pattern indices, taking Longnan City of Gansu Province as an example, with the help of ArcGIS and GeoDa spatial analysis tools, starting from the number, size, morphology and spatial proximity, the distribution characteristics of rural settlements on different spatial scales were explored. The results showed that detached house and small settlements in Longnan accounted for 79.25% of the total rural settlements, while the large and medium-sized settlements, though in small number, accounted for 79.66% of the city’s rural settlement area. The midwest of Xihe county and the middle of Hui county were hot areas where quantity and area of rural settlements per unit area of land were high. The scale of rural settlements in the east-west direction presented a feature that the middle was larger than the east and west, and the rural settlement in the east was slightly larger than that in the west, besides, in the north-south direction, it presented a slow growth trend from south to north. Overall, the forms of rural settlements in Longnan mountainous area were not regular, but there was a narrow regular band located in the western end of this area. The rural settlements shape index in Longnan had the characteristics of high value and high value aggregation, low value and low value aggregation. Land was generally occupied intensively by rural settlement in Longnan, there were 1937 villages with significantly aggregated settlements, accounted for 61.16% of total villages in this city, and showed significant aggregation in spatial distribution.