Abstract: The variation of atmospheric composition exerts an important impact on weather, climate, environmental ecology, human health and social life. Only through long-term observation and understanding of the concentration, variation trends and related source and sink processes of these atmospheric components we can accurately assess the impact of human activities on the current earth’s climate, environment and ecosystem, and protect human development and living conditions. In this paper, the development of atmospheric background observation in China and Global Atmospheric Watch of World Meteorological Organization (WMO/GAW), establishment and operation system of atmospheric background station network in China Meteorological Administration (CMA), as well as the important role that atmospheric background observation plays in scientific research, government policy making, social public services and other fields are introduced. In addition, based on the analysis on the variation trends and characteristics of greenhouse gases, particulate matter (PM) and O₃ observed by atmospheric background station, the significance of atmospheric background observation in climate change, air pollution control, carbon emission peak and carbon neutrality in China is elaborated. At last, suggestions are put forward in promoting the construction, layout and operational system of atmospheric background stations, enhancing the capacity and expanding the application services of atmospheric background observation. The latest observation of greenhouse gases from atmospheric background station in China by 2020 show that the annual average concentrations of CO₂, CH₄ and N₂O at the Global Atmospheric Background Station in Waliguan, Qinghai, are comparable to the average concentrations in the middle latitudes of the Northern Hemisphere, while the concentrations of CO₂ and CH₄ at the six regional atmospheric background stations are all higher than those at Waliguan Station, which reflects the important contribution of human activities to atmospheric composition at regional atmospheric background.