The decade from 2010 to 2019 marked a significant turning point in China’s history of environmental regulation and pollution. This article describes the recent trends in air and water quality, with a focus on the five years since China declared a “war on pollution” in 2014. It summarizes the emerging literature that has taken advantage of accompanying improvements in data availability and accuracy to document sharp improvements in environmental quality, especially local air pollution, and understand their social, economic, and health consequences.