During 2014During -2016, this study investigated the atmospheric PM 2.5 , R M , PM 2.5 /PM 10 , PCDD/Fs-WHO 2005 -TEQ, and PM 2.5 -bound total-PCDD/Fs-WHO 2005 -TEQ content of 22 cities in northern China. In general, the more highly industrialized cities had higher PM 2.5 concentrations. The lowest three-year average concentrations of PM 2.5 occurred at Lhasa and Qiqihar, and were 25.2 and 36.7 µg m -3 , respectively, while the highest concentrations of PM 2.5 occurred at Baoding and Shijiazhuang, and were 106 and 102 µg m -3 , respectively. From 2015 to 2016, the PM 2.5 concentrations of most cities decreased, but those of several others (Shijiazhuang, Taiyuan, Yinchuan, Lhasa, Sinning, Urumqi, Weinan and Xian) increased, suggesting that the air quality of these was still not well controlled. The average of R M values of the 22 cities were 7.2, 6.5, and 6.1 in 2014, 2015 and 2016, respectively, which means the PM 2.5 concentrations in northern China were much higher than the WHO air quality regulated standard (10 µg m -3 ). A city with a higher PM 2.5 concentration always had a higher PM 2.5 /PM 10 ratio. Among the 22 cities, the six highest three-year averages of total-PCDD/Fs-WHO 2005 . The PM 2.5 concentrations, R M values and PCDD/Fs-WHO 2005 -TEQ concentrations in the cities of northern China are higher than those in the south, indicating that the air quality in the north is worse than in the south. The results of this study provide a theoretical basis for proposing air pollution control strategies and improving the atmospheric environment in China.