Inefficient water use in Yunnan Province was revealed by severe drought lasting  for three consecutive years since 2009. The relative efficiency of water use in Yunnan province is calculated and analyzed by data envelopment analysis(DEA) method on the basis of water resources and socio-economic indices of Yunnan province collected through tabular survey method. Results show that the water use efficiency in Yuxi, Chuxiong, Dali, Qujing, and Baoshan are slightly higher than that of the other autonomous regions and municipalities which could draw lessons from the experiences of the above 5 cities to address the acute water shortage. Lincang City in particular, should make more efforts to improve the water use efficiency. Strengthening technology investment is the first priority in improving water use efficiency. Measures of expanding the industrial scale and optimizing the industrial structure are also given.