Through the analysis of the characteristics of ozone (O₃) pollution and the meteorological influencing factors in Nantong from 2014 to 2017, a prediction model of O₃ concentration in different months was established, and the related high concentration O₃ synoptic situations were also summarized. The results showed that the day number of O₃ pollution in Nantong was increasing obviously from 2014 to 2017. O₃ concentration had a significant positive correlation with temperature, sunshine hours and other factors, but a negative correlation with relative humidity, total (low) cloud amount and wind speed. High O₃concentration were likely to occur with the temperature higher than 20℃, the relative humidity less than 60%, the sunshine hours more than 4 hours, the average low cloud less than 40%, the wind speed less than 6 m/s. The synoptic systems affecting O₃ pollution were classified into 6 patterns, including edge of subtropical high, interior of subtropical high, back of upper-level trough, front of upper-level trough, upper-level ridge and vortex. Considering all meteorological factors, three O₃ concentration prediction equations were established respectively from April to May, June to August and September to October. Using the data of 2017 to test the prediction equation, it was found that the correlation coefficients between the predicted and the observed values were 0.76, 0.74 and 0.65 (P<0.01), respectively, indicating the good fitting effect and predictability. Cluster analysis of backward trajectory showed that the largest ratio of air flow passed through the Yangtze River Delta region with relatively serious O₃ pollution, favoring the transportation of pollutants.