Abstract: Based on the vegetation map and the relief map, using GIS and Fragstats, the spatial pattern of forest landscape of Xishui reserve in Qilian Mountains were analyzed. The results showed that the distribution of the vegetation was impacted mostly by altitude and aspect, grassland was mostly distributed on the land of altitude 2 500～2 900 m and aspect of south and southwest,Picea crassifolia forest was always in the land of altitude 2 900～3 300 m and aspect of north, northeast, east and northwest, and shrubbery was in the land of altitude 3 300～3 700 m. The grassland had the biggest area and its connectivity and integrality were the best. The biggest MPFD of Picea crassifolia forest meant that its shape was the most complicated, its mean patch area was small, and the distance between the patches was short. So Picea crassifolia forest was easy to be impacted by some disturbance. The forest suitable land and Sabina przewalskii forest showed more outstretched characteristics than farmland and land with few trees. The mean nearest-neighbor distance of the poplar forest was the biggest in all the landscape elements, so the poplar forest's fragmentized degree was the highest in all the landscape elements.

Key words: Mountain forest landscape, Landscape pattern, Landscape indices, Qilian Mountains, Xishui Natural Reserve