Abstract:[Objective] The study aims to evaluate the investment efficiency in reclaimed water projects in different regions of China with consideration of social and environmental benefits of the investment, and intend to propose differentiated improvement strategies for different regions. [Methods] This study selected 22 provinces, 4 municipalities and 5 autonomous regions(excluding Hongkong, Macao Special Administrative Region and Taiwan Province) as the research objects and used DEA model and Malmquist index model to calculate the investment efficiency. [Results] The investment efficiency in reclaimed water in China was 0.858, and the efficiency was uneven among different provinces. The investment efficiency of reclaimed water in China is normal and it still has room to be improved. Investment efficiency of reclaimed water considering economic, social and environmental benefits is higher than that considering only economic efficiency. [Conclusion] Regional development is unbalanced, the investment efficiency is different among provinces due to different reasons. Therefore, provinces should be divided into different categories and different technology, management, policy and comprehensive improvement strategy should be proposed and carried out.