Fine particles (PM_2.5) and particulate matter (PM₁₀) monitoring data from 2015 to 2016 in 18 major cities in the Yangtze River Delta were analyzed to determine the temporal and spatial distribution characteristics of PM_2.5 and PM₁₀ pollution in the Yangtze River Delta urban agglomeration, China. The results showed that the cities with the most serious PM_2.5 and PM₁₀ pollution were mainly distributed along the Yangtze River in Jiangsu Province, while the lowest concentrations of PM_2.5 and PM₁₀ were measured in Zhoushan of Zhejiang Province. The PM_2.5 and PM₁₀ concentrations in 2016 were lower than those in 2015. In 2015 and 2016, the PM_2.5 and PM₁₀ concentrations were the highest in winter, followed by spring, and the concentrations were the lowest in summer. In 2015 and 2016 the average annual concentrations of PM_2.5 and PM₁₀ were lower than the ambient air quality standard of China (Grade II; PM_2.5: 35 μg/g and PM₁₀: 70 μg/g) in Zhoushan only, but were higher than the particulate pollutant emission limits of the United States and the European Union. The ratios of PM_2.5/PM₁₀ in the urban agglomeration were greater than 0.5, indicating that the pollution in the atmospheric particulate matter in the Yangtze River Delta was generally less than 2.5 μm.