Abstract: CBM-Z chemical mechanism was used to simulate ozone diurnal concentration at 325-m meteorological tower in the Institute of Atmospheric Physics, Chinese Academy of Sciences, and evaluated the influences of meteorological conditions, control measures, and precursors of ozone on concentration of surface ozone. The results show that CBM-Z chemical mechanism reproduces diurnal concentration of ozone, nitric oxide, and nitrogen dioxide at the 325-m meteorological tower during Beijing Olympics well, there are very similar meteorological conditions while local ozone episodes occur, Volatile Organic Compounds(VOCs) and nitrogen oxides emissions reduced through practicing environmental control measures, which induce apparent reduction of surface ozone concentration, and the key factors which affecting the concentration of ozone are VOCs and carbon monoxide.