Abstract: Ambient air quality criteria is an important basis for the ambient air quality standards. It is also the scientific basis for improving atmospheric environmental quality, protecting public health, and carrying out precise management of the ecological environment. Taking ozone as an example, the present study provides a comprehensive overview of the origin and development of ambient air quality criteria, and systematically elaborates the concept of ambient air quality criteria. The research results show that the essence of ambient air quality criteria is to explore and analyze the relationship between air pollutants and their impacts, and prove the supporting roles of ambient air quality criteria in the expression of ambient air quality standards, the setting of concentration limits, etc. This study summarized the existing ambient air quality criteria system framework and research priorities, which provides a reference for conducting air quality criteria research in China.