Abstract: Principal component analysis (PCA) was used to analyze of Wuqi County statistics ranging from 1949 to 2007 to identify the main drivers of variations in cultivation, especially after the implementation of the Grain for Green program. The analysis examined the stages in cultivated land use, impact trends, and changes in the industrial structure. Results showed that, from 1949 to 1998, the main factors affecting farmland area became increasingly complicated and the number of principal components needed for analysis increased; however, with the implementation of Grain for Green in 1999, the components needed for analysis decreased. The contribution of the first principal component increased over time from 54.315% to 82.704%. The Grain for Green program can greatly influence farmland and local economies may depend too much on the hydrocarbon industry.