Abstract: Utilizing the online monitoring data of volatile organic compounds (VOCs) in Sanya in 2019, the pollution characteristics and sources of VOCs, and the effects of VOCs on O₃ were comprehensively analyzed to investigate the pollution characteristics of VOCs in the ambient air in tropical regions. The results showed that: (1) The daily average mixing ratio of total volatile organic compounds (TVOCs) ranged from 2.05×10^-9 to 19.74×10^-9, and the composition was dominated by alkanes (71.4%) and olefins (20.5%). (2) The diurnal variations mixing ratio of dominant VOCs species such as propane, n-butane, isobutane, ethane, ethylene, acetylene, benzene and toluene, showed obvious bimodal distribution in the morning and evening. The diurnal variations mixing ratio of isoprene was significantly higher during the day than at night, and the seasonal variation was basically consistent with the changes of light. (3) The greatest contribution to ozone formation potential (OFP) was alkenes (70.6%), of which isoprene contributed the most (41.9%), followed by alkanes (19.9%). (4) The concentration of VOCs and NO₂ in spring and summer was low, and it was difficult to generate high concentration of O₃ through photochemical reaction. The significant increase in O₃ concentration in autumn and winter was mainly related to the transmission of pollutants in the northeast. (5) Six sources were extracted by positive matrix factorization (PMF) model: traffic source (46.52%), solvent usage source (18.25%), plant source (12.36%), industrial source (11.99%) and combustion source (10.88%). Overall, the concentration of ambient VOCs in Sanya was strongly influenced by traffic sources, and the control of VOCs emitted from motor vehicles should be strengthened to reduce the active components of atmospheric VOCs in Sanya, thereby reducing the generation of O₃.