Abstract: Based on the hourly data of O₃ concentration and meteorological data in Tangshan from 2016 to 2019, the characteristics of O₃ pollution and its relationship with meteorological conditions were analyzed.The results show that the number of days when the concentration of O₃ exceeds the threshold value in Tangshan is 53 days in 2016 and that in 2017 to 2019 is more than 70 days per year, so the pollution degree is high.The monthly average concentration of O₃ shows a bimodal distribution.The concentration of O₃ is the highest (with 112.26 μ g ·m^-3) in June, followed by September.The days with the concentration of O₃ exceeding the standard occur from March to October, and mostly happen in summer, followed by spring and autumn.The concentration of O₃ reaches its maximum at 15:00, and shows a unimodal distribution during the day.O₃ concentration is positively correlated with temperature and wind speed, and negatively correlated with relative humidity.High temperature is an important factor leading to excessive concentration of O₃.When the daily maximum temperature exceeds 25℃, it should be considered that the concentration of O₃ exceeds the standard.When the relative humidity is about 50% and ranges from 60% to 80%, the overstandard rate of O₃ concentration is more than 30%.When the relative humidity is 60% to 70%, the average concentration of O₃-8h reaches the maximum.The over standard rate of O₃ concentration in summer and autumn is related to the surface breeze and lower mixing layer height during the daytime.When the average wind speed during the day is greater than 1 m · s^-1 and less than or equal to 4 m ·s^-1, the overstandard rate of O₃ concentration is higher.The weather situation prone to moderate or above O₃ pollution is influenced by northwest airflow or high-pressure ridge at 500 hPa, and southwest or south airflow passes through at 850 hPa.The ground is mostly in the rear of high pressure, front of the low pressures, or convergence area of low pressure.