Abstract: The pollutants concentration data of five automatic air quality monitoring stations from Beijing in 2016, including Changping monitoring station, West Park Officials monitoring station, Shijingshan city monitoring station, Yufa monitoring station and East 4th Ring Road traffic monitoring station, were analyzed to investigate the air quality and the regional transport characteristics of PM_2.5 from outside of Beijing. The HYSPLIT and WRF-CAMx-PSAT model were used to analyze the air flow of different seasons and the trans-boundary contribution of PM_2.5 to Beijing in different seasons, respectively. Results show that the temperature, visibility, relative humidity, wind speed and barometric pressure increase by 5.6%, 8.7%, 3.6%, -4.0% and 0.03%, respectively, in 2016 compared with that in 2011-2015. Moreover, southward air flow trajectory of spring, summer and winter accounts for 14%, 9% and 4%, respectively, indicating the favorable meteorological conditions. Further investigation show that the month average concentration of O_{3-1 h} is higher from April to September than that of other months. The monthly average concentrations of PM_2.5, NO₂, CO and SO₂ are the highest in winter, while the average concentrations of PM_2.5, CO and NO₂ are the lowest in February. The spatial distribution analysis indicates that the concentrations of PM_2.5, SO₂, O_3-1h and CO display non-uniform distribution and decline from south to north, while the NO₂ concentration is higher in urban than that in suburb. Based on the analysis of the relationship between meteorological factors and the pollutants, it is found that PM_2.5 and relative humidity, O₃ and temperature, CO and relative humidity are significantly positive linear correlation, and the NO₂ exhibits dramatically relationship with relative humidity compared with that of SO₂. Meanwhile, through the analysis on the PM_2.5 transport characteristics of typical pollution process, it is found that the PM_2.5 of Beijing is mainly from local emission sources, with percentages of 36.4%-56.8%. The contributions from Hebei, Tianjin and other regions are also considerable, with proportion ranges of 22.6%-47.9%, 3.16%-17.8%, and 9.7%-16.7%, respectively.