Abstract:The increase of surface ozone concentrations in summer is raising the risk on ecosystem health. Site sampling based near-surface ozone concentration has been well analyzed in Beijing. However, very scant work has been done to reveal the continuous changing pattern at urban and rural gradient. Thus, in this research, using mobile vehicle equipped with ozone analyzer,we monitored the ozone concentrations in a typical urban-rural gradient, from central urban to north-west rural gradient of Beijing on typical ozone polluted days in summer, meanwhile, ozone concentrations at Beijing Teaching Botanical Garden which worked as the control was monitored and applied. The location including longitude and latitude of mobile vehicle, the ozone concentrations of the samplers and control sites were obtained at the same start time and frequency. Mean NDVI within each site's 50 meters' buffer was correlated with the ozone concentration. Additionally, to discern the climatic mechanism of ozone distribution pattern of the monitoring days, we did synoptic type analysis using GrADS 2.1 and analyzed the backward air mass trajectories using HYSPLIT model. Results followed:(1)the ozone concentrations were significant higher in north-west mountains than those in other urban and suburban areas. The sequence is:North-west mountain region(254.68μg/m3) > control site, Beijing Teaching Botanical Garden(220.89μg/m3) > branch urban road(162.84 μg/m3) > urban main road and freeway(103.24 μg/m3);The landmark is Min tomb and the ozone concentrations north-west to this break point, where is mountains, were about 2.00 times than those measured at the urban and suburban regions. (2) the distribution of plants affects surface ozone pattern. In the same time, ozone concentrations increase with NDVI with a significant Logistic relationship. (3) the spatial variability coefficients of ozone concentrations in mountain regions were lower than those in free way, urban motor road and branch road; the coefficients in mountain area is 0.11, on branch road of urban is 0.28, on main motor road of urban is 0.26, on free way is 0.36; (4) The precursors of ozone in the north-west Mountains were partly from the urban region due to wind. Large scale uniform pressure field, the background of high pressure field, and the forward of low pressure easily lead to weak south or south-east air flow, which pushed air from urban to north-west rural region, and might partly explain the cause of the ozone pollution pattern in summer in Beijing urban and rural region.