Abstract: Based on the data from the environmental monitoring stations and weather stations in Chengde from 2014-2016,the influence of meteorological conditions on the concentration of O₃-8h was analyzed.The forecasting method of meteorological conditions for O₃ pollution was discussed.The results show that the concentration of O₃-8h from April to July is higher than that in the other months in Chengde.The diurnal variation of O₃ concentration is characterized by the high concentration in the afternoon and the low one at night.When the O₃ pollution happens,it is affected together by the high-pressure ridge and the west airflow at 500 hPa,the strong warm advection and high temperatures above 20℃ at 850 hPa,and the southerly airflow between the low-pressure front and the high-pressure rear at sea level pressure field.The meteorological factors that are favorable to increase the O₃ concentration are as follows:the daily mean temperature is higher than 23℃;the daily maximum temperature is higher than 28℃;daily mean sea level pressure is 995-1007 hPa;the daily average water vapor pressure is 18-28 hPa;and southerly wind is greater than 1 m·s^-1.Based on the comprehensive score of meteorological factors,the O₃ pollution index is established.The correlation coefficient between O₃ pollution index and O₃ concentration is 0.7553,which indicates that the O₃ pollution index can be used to predict the ozone pollution weather.