Abstract:The paper concerns the effect of increase atmospheric ozone contents(100 and 150 nl·L-1)on the soil enzymatic activeness in the growing/development(G/D) period including jointing,booting,heading,milking and mature stages of winter wheat. Results suggest that as a G/D stage is progressing,the activities of soil catalase and polyphenol oxidase display first decline and then rise,with a minimum at the heading and higher activity at the elongation and maturity,and the activeness of invertase and urase displays first increase and then decrease,with their maxima in the heading stage,followed by sharp drop.Variance analysis shows that under the stress of ozone,the activities of catalase,polyphenol and invertase in the mature stage are greatly higher than those of the P<0.05 OTC control.Urase activeness treated only by high-concentration ozone in the previous G/D period are significantly higher than those of the control experiment.