基于1990—2018年4期Landsat卫星30 m分辨率土地利用数据，结合土地利用变化分析法及统计学方法，对祁连山甘肃片区近30年土地利用时空分布特征进行了分析研究，探讨了自然因素和人类活动对研究区土地利用变化的作用机制。结果表明：（1）祁连山甘肃片区土地利用类型以未利用土地和草地为主；1990—2018年研究区水域和未利用土地面积为减少趋势，其他土地利用类型面积呈动态增加趋势。（2）2000年后，参与土地转移的面积增加，以未利用土地—草地、未利用土地—林地、耕地—草地这3种转化关系为主。（3）自然因素是祁连山甘肃片区土地利用变化的主导因素，以“三北”防护林工程、“天保”工程和退耕还林还草为主的生态工程在限制了人类农牧业生产活动的同时，给祁连山甘肃片区土地利用变化带来明显的局地效应。

Based on Landsat 30m land use data from 1990 to 2018， combined with the land use change analysis and statistics method， the spatial and temporal distribution characteristics of land use at the Gansu part of the Qilian Mountain in recent 30 years were studied and the function mechanism of natural factors and human activities on the land use change in the area was explored. The results show that： （1） The land use types in Gansu part of the Qilian Mountain were mainly unused land and grassland； from 1990 to 2018， except the water and unused land areas which showed decreasing trends， the areas of other types showed a dynamic increasing trend. （2） After 2000， the areas and types of the land participating related transfer were increasing， mainly between unused land-grassland， unused land-woodland and cultivated land-grassland. （3） Natural factors were the leading reasons for the land use changes in Gansu part of the Qilian Mountain. The ecological projects Three- north Shelterbelt Project and Natural Forest Protection Project which focused on returning farmland to forest and grassland， returning grazing land to grassland， restricted human agricultural and animal husbandry production activities， and also brought obvious local effects on the land use change in Gansu part of the Qilian Mountain.