Abstract: Government procurement policy, as one of the important environmental policies in the world, has attracted widespread attention in recent years. For a long time, the Chinese government has taken environmental protection and energy conservation as one of the important goals of government procurement policy, and fruitful progress has been made in practice. However, the scientific evaluation of the effects of government procurement policy on the improvement of environmental quality is rarely involved. In this study, the important scientific question of whether the policy of 30 provinces and cities in China have improved the environmental quality is explored by constructing spatial econometric models based on Chinese provincial panel data (2001-2017). The research finds that: (1) Environmental pollution in China has a significant spatial correlation in geographical space. (2) The empirical results indicate that Chinese government procurement policy has a positive correlation with the degree of regional environmental pollution with a significant level of less than 10%, which shows that the effect of Chinese government procurement policy in promoting regional environmental quality improvement is not obvious in general. (3) Before and after the establishment of the government compulsory procurement system of energy-saving products and the accession to the government procurement agreement (GPA), the effect of Chinese government procurement policy on the improvement of regional environmental quality has significant differences. Before that, there is a significant positive correlation between the government procurement policy and the degree of environmental pollution, indicating that the expansion of government procurement inhibits the improvement of environmental quality; but after that, there is a negative correlation between the two, which is significant at the level of 5%, which shows that the government procurement policy has an obvious effect on environmental quality in recent years. Finally, this study puts forward policy implications from the aspects of strengthening the system design, improving the legal system of government green procurement; using international rules rationally to build a procurement system in line with China's interests; setting up green procurement departments, improving the performance evaluation and supervision mechanism of rewards and punishments, in order to provide a scientific basis for the improvement and perfection of Chinese government procurement policy in the future.

Key words: public procurement, environmental quality improvement, spatial econometrics, environmental pollution index