Abstract: The alternating evolution of industrialization and urbanization has led to a complex land use pattern in the Pearl River Delta and its surrounding areas.The rapid urbanization process has intertwined urban built-up areas with a large number of village and industrial zones.Such change inevitably increases the complexity of the composition and spatial heterogeneity of volatile organic compounds (VOCs),and has an impact on the spatial and temporal variability of ozone (O₃) pollution.To clarify the spatial heterogeneity of such emissions and its impact on O₃ pollution,Longtang (LT) and Institute of Technology (IOT),which can represent typical industrial and urban built-up areas in Qingyuan City,respectively,were selected for observation and analysis in this study.The results showed that there were large spatial differences in concentration levels and pollution characteristics of VOCs.The daily average concentration of VOCs at the LT was 30.42×10^-9,which was higher than that at IOT (17.32×10^-9).The ozone formation potential (OFP) of xylene and toluene at LT were 57.6×10^-9 higher than that at IOT,which was equivalent to the sum of the OFPs of the top ten species OFPs at IOT.Meteorological analysis showed that the two sites were not upwind or downwind from each other,but were jointly exposed to local air masses.Source apportionment results suggested that emissions were endogenous to this spatial heterogeneity,with traffic sources dominant at IOT,while industrial-related emission sources contributed more at LT.The O₃ production rates at the two sites were further simulated and the consistency of the O₃ time series at the surrounding sites was compared.The results showed that O₃ was less variable at the local scale.The sites with high VOCs emissions had higher contribution to local O₃,and the O₃ formation process also varied widely among sites within the local area.The prevention and control of O₃ pollution were put forward based on this study.In the short term,the important contribution points of O₃ pollution should be found through technical means and observational data.And targeted clean-up and treatment of scattered pollution and comprehensive regulation of industries involving VOCs should be carried out.In the long term,the urban development and industrial layout should be planned scientifically and rationally,and urban ventilation corridors should be reserved to effectively reduce the generation of O₃ pollution.