Abstract: Objective To assess the air quality in an industrial harbor area located in Tangshan city in order to provide fundamental data for carrying out continuous environmental monitoring.Methods According to the construction status and the distributions of pollution sources in the area,steel factory,power plant,crude oil dock,ore dock,coal dock,and control area were chosen as the sampling area.The concentrations of SO₂,NO₂,CO,O₃,total suspended particulate(TSP) and particulate matter < 10mμm(PM10) in the ambient air were determined.The air quality of each area selected and of the whole industrial area were assessed by calculating the integrated air pollution index.Results The concentrations of all air pollutants in each area as well as in the whole industrial area were lower than the maximum acceptable level defined by standards for environmental air quality.Compared with the control area,the concentration of TSP of coal dock was higher with a significant difference(0.416 vs 0.193 mg/m³,P <0.05).The integrated air pollution indexes for ambient air of steel factory,power plant,crude oil dock,ore dock,and coal dock were 0.486,0.451,0.350,0.314,and 0.475,respectively.Air quality index of each area and the whole industrial area were all lower than 0.49,and the quality of the ambient air was gradeⅠ,which belonged to clean air.Conclusion The ambient air quality of the industrial harbor area was clean and belonged to gradeⅠ.