Increasing attention has been paid to the air pollution more recently.Smog chamber has been proved as a necessary and effective tool to study atmospheric processes,including photochemical smog and haze formation.A novel smog chamber was designed to study the atmospheric photochemical reaction mechanism of typical volatile organic compounds (VOCs) as well as the aging of aerosols.The smog chamber system includes an enclosure equipped with black lights as the light source,two parallel reactors (2 m3 of each) with separate control of light source and temperature,with a series of coupled instruments for online monitoring of gas phase and particle phase reactants and products.Chamber characterization,including air source stability,effective light intensity,temperature stability,as well as gas phase and particle phase wall losses,were carried out before further research.The results showed that our smog chamber systems developed by other domestic and international groups.It was also observed that the wall loss of aromatic VOCs varied with different functional groups as well as the isomerism.The results of preliminary simulation experiment from styrene-NOx demonstrated that the chamber can be well utilized to simulate gas-particle conversion progresses in the atmosphere.