Agriculture is an important part of the economic development in the northwest arid area. Research on the cultivated land change is particularly important to the development of the economy in Northwest. Based on the data from landuse change survey and socio-economic statistic data in Gansu Province in nearly two decades,the situational development of cultivated land resource and spatial patterns were analyzed under the support of GIS and remote sensing and the grey correlation analysis was made to find the main factors to cultivated land change. Results showed that the correlations of the change in cultivated land and the factors of economic development level,two tertiary industries,and agricultural structure adjustment were as high as 0.898,0.892,and 0.883,respectively. Finally,each impact factor was deeply analyzed and some comments and suggestions were given for sustainable utilization of cultivated land resource in Gansu Province.