O3 concentrations were well negatively correlated with NO, NO2, NOx and CO during day time, but correlation of night time is discreased because of complex variation of precursors.

• NO、NO2和CO作为O3的前体物，昼间其浓度与O3浓度呈线性负相关，夜间相互作用较为复杂，相关性显著降低；