To investigate the effectoffine particulate matter(PM2.5)on vascularendothelialgrowth factor(VEGF)and reactive oxygen species(ROS)in bronchialepithelialcells.M ethods Bronchialepithelialcells 16HBE werecultured and divided intosalinecontrolgroup,25 μg/mlPM2.5 group,50 μg/mlPM2.5 group and 100μg/mlPM2.5 group.Cellproliferation activity and expressions ofROS and VEGF were measured in each group.Results In the 50 μg/mlPM2.5 group and the 100 μg/mlPM2.5 group,cellproliferation activity was (89.80 ±5.85)% and (77.20 ± 7.70)% respectively,which wassignificantly lowerthan thatin the saline controlgroup( <0.05);ROS levelwashigherthan thatin the saline controlgroup afterexposure for12 and 24 h( < 0.05),amongwhich the 100 μg/mlPM2.5 group had the highestROS levelafter12-h and 24-h exposure [(16.60 ± 0.40)and(24.01 ± 0.55) respectively]. In the 50 μg/ml PM2.5 group and the 100 μg/ml PM2.5 group, VEGF protein expression washigherthan thatofthesalinecontrolgroup ( < 0.05),amongwhich VEGF protein expression level in the100 μg/mlPM2.5 group wasthe highest(0.892 ± 0.028).Conclusions PM2.5 can cause oxidative damage to bronchialepithelialcellsand up-regulatetheexpression ofVEGF protein.