The atmospheric concentrations of carbonyls and BTEX (benzene, toluene, ethylbenzene, m,p-xylene and o-xylene) were measured simultaneously in summers of Beijing from year 2008 to 2010. The total concentrations of formaldehyde, acetaldehyde and acetone in the consecutive summers, which were 33.4 mu g m(-3), 36.7 mu g m(-3) and 48.6 mu g m(-3), respectively, were much lower than those reported in the summers of 2005 (58.4 mu g m(-3)) and 2006 (77.4 mu g m(-3)). The concentrations of BTEX in the summers were 16 mu g m(-3), 21.5 mu g m(-3) and 15.4 mu g m(-3), respectively. The maximal contributions of photochemical reactions to atmospheric formaldehyde and acetaldehyde in the summers were estimated to be around 47.6-60.3%. The average ozone formation potentials (OFPs) for carbonyls and BTEX as well as carbon monoxide in summer of Beijing were calculated as 166.1 mu g m(-3), 65.4 mu g m(-3) and 100.8 mu g m(-3), respectively. (C) 2012 Elsevier Ltd. All rights reserved.