In this study ozone and meteorological factors were measured at an urban station and a downwind rural station around Beijing from June 2005 to September 2006. The ozone at urban station exhibited stronger diurnal and seasonal variations than that at the rural station. The maximum concentrations of ozone were 198.9 x 10(-9) and 151.2 x 10(-9) at Beijing and Xinglong, while there were 171 hours and 255 hours in which ozone exceeded the China's norm, respectively. 90% of the exceeding occurrences happened before 16:00 in Beijing, while more than 82% happened at night in Xinglong. The peak concentration of ozone at Xinglong in the diurnal cycle was 3-4 hours lag of that at Beijing because of the influence of air mass from Beijing. Double ozone peaks phenomena can be found at Xinglong due to the mountain-valley breezes especially in the summertime. Stagnant meteorological conditions and mountain-valley breezes can cause ozone accumulation at downwind areas. The AOT40 values were 23.1 x 10(-6) x h, 26.5 x 10(-6) x h, and 14.1 x 10(-6) x h in spring, summer and autumn respectively at Xinglong, which could cause more than 30% lose in wheat yields.