In this study, panel data from 12 provinces and autonomous regions in western China during the period from 2007 to 2014 were selected, and the super SBM-undesirable model, which is part of the data envelopment analysis method, was used to analyze the evolution trend of water resources utilization efficiency and potential for resources saving and emissions reduction in these provinces and autonomous regions. The Tobit regression model was used to analyze the main factors influencing the utilization efficiency of water resources. The results of the study show that the overall status of water resources utilization efficiency in western China is at a low level. There are significant differences between different provinces and autonomous regions: the water resources utilization efficiency in Chongqing, Shaanxi, and Sichuan is relatively higher than in Gansu, Xinjiang, and Guangxi, where there is a declining trend. Agricultural water utilization has the greatest potential for the improvement of water resources utilization efficiency, followed by ecological water utilization, industrial water utilization, and domestic water utilization. The discharge of chemical oxygen demand(COD)in sewage in Xinjiang, Gansu, Guangxi, Guizhou, Qinghai, and Yunnan should be reduced further. In addition, the water utilization efficiency exhibits a significantly negative correlation with the proportion of secondary industry and a significantly positive correlation with the sewage treatment rate. The water resources endowment and GDP have no significant effect on the water resources utilization efficiency.