Scientifically evaluating the policy effectiveness of the pilot reform of water resource tax is an important means to promote the efficient utilization of water resources and improve the green tax system. Based on water resources data and macroeconomic data from 31 provinces in China from 2008 to 2023

this article uses multi period difference-in-differences method and synthetic control method to test the impact of water resource tax reform pilot on water-using intensity and structure. The empirical results show that the water resource tax reform significantly increased the surface water-using rate in pilot provinces

reduced the groundwater use rate

and optimized the water-using structure

but the suppression of water-using intensity didn't see effect. As for regions

there are significant differences in the effectiveness of water resource tax reform. The water-using structure in most pilot areas(6 provinces) has been improved

but there is no sign of a decrease in water-using intensity. Therefore

in order to maximize the policy effectiveness of the pilot water resource tax

it is necessary to continuously strengthen tax incentives related to water resources

improve the water resource tax system

in order to promote the rational and efficient use of water resources

and assist in water resource protection.