Continuous observations of six types of pollutants( PM2. 5,NO,NO2,O3,CO and SO2) were conducted at Baolian station in Beijing from2009 to 2012. Weekly cycle of these pollutants and their concentration differences between the two special annual public holidays( Chinese New Year and National Day) and non-holidays were examined. Weekend and holiday effects were significant for all pollutants,with higher O3 concentration over the weekend and holidays while higher concentrations for all other pollutants during t...