Abstract: This paper studies the efficiency and influencing factors of interprovincial water use in China, and provides reference for the construction of a water-saving society. First, an improved data envelopment model is used to calculate water use efficiency in different regions from 2015 to 2020. Then, compared with the results of ordinary least square regression, quantile regression is used to explore the influence of various factors on water use efficiency at different grades. The results show the average water use efficiency in China fluctuated around 0.45, showing an inverted "U" shaped trend. Regional water use efficiency is eastern, central and western in descending order. Water use efficiency is impacted significantly by natural factors, economic development level, sustainable use level, scientific and technological progress, human literacy, and enterprise cost. Among them, the impact of water endowment is significant on the areas with low water efficiency, while it is not significant on the areas with medium or high efficiency, which is different from the "resource curse" hypothesis. Thus, there is still much room for improvement in China's water use efficiency, especially in the low efficiency areas.

Key words: water resources utilization, influencing factors, data envelopment analysis model, ordinary least squares regression, quantile regression