Abstract: Abstract : China, South Korea and even Northeast Asia are confronted with the urgent needs and challenges of air quality improvement. Air pollution prevention and control has become hot topics in international exchange and cooperation. To jointly deal with the air quality issue, China and South Korea have explored a practical and efficient collaboration paradigm focusing on cooperation mechanism innovation, common platform building, flagship project design, and joint research since 2019. The collaboration paradigm has broken the "five barriers" of the two sides in the aspects of organization, region, subject, information and technology, and achieved the sharing of policy, technology, data, information and results. The China-South Korea cooperation has also contributed to the air quality improvement of the two countries and region, and provided valuable experience in the thematic area of environment for promoting the practice of “building a community with a shared future for mankind” at the regional level. This article analyses the needs and challenges of air quality improvement in China and South Korea from 2015 to 2019, comprehensively summarizes the progress and achievements in China-South Korea cooperation from 2019 to 2021, as well as the overarching, forward-looking, and replicable cooperation paradigm, and illustrates the impact in strengthening capacity, responding to social concerns and dispelling misunderstanding, and supporting multilateral environmental diplomacy. Based on the needs and trend of atmospheric environmental governance in Northeast Asia, this paper puts forward outlook and suggestions for strengthening regional cooperation in Northeast Asia, and suggests that China and South Korea should continue advancing the bilateral cooperation in the atmospheric field, establish a new environmental cooperation pattern of "China-South Korea Plus", and offer China-South Korea wisdom and solutions to the global community.