Circulation weather types were identified over the Beijing-Tianjin-Hebei (BTH) region during winter based on sea surface pressure fields from ERA-Interim reanalysis dataset from 2013 to 2015 using the PCT (principal component analysis in T-mode) method. The characteristics of air pollution associated with key meteorological parameters under different atmospheric conditions was analyzed using the corresponding time period of air pollution data and conventional meteorological observations. Also the causes of the occurrence of high pollution episodes and the characteristic weather features over the BTH region were investigated by analyzing typical data collected in the most polluted month. The results showed that there were nine main circulation types over the BTH region, i.e., non-polluted circulation types with high pressure to the front of the BTH region or to south of this region, and polluted circulation types with high pressure fields, the rear of high pressure, col pressure field or ahead of the cold front. Overall, the polluted circulation types were characterized by high relative humidity with weak winds, high stable energy and low maximum mixing depth, which reduced the possibility of dilution of pollutants from the local area, therefore, the observed averaged air quality index (AQI) values in most cities were above 150. Two heavy air pollution episodes occurred in February 2014 caused by the persistent high pressure fields which lasted for a few days. The evolution of the high pressure system led to strengthening of the northerly wind, which reduced the concentrations of pollution over north cities of the BTH, however, southerly winds carried air pollutants to make the concentration increase rapidly in the north cities of the BTH.