Abstract: The volatile organic compounds (VOCs) in the ambient air in Maoming have been researched with the method of sorption/ thermal desorption-GC/MS . The results show that 130 or more VOCs exists in Maoming, most of which are alkane,aromatic hydrocarbon ,alkene and halohydrocarbon ,and 1 4 of which are hazardous . The characteristic VOCs emittedfrom Maoming Oil Refinery are cycloparaffinic hydrocarbons . Hexane ,1 ,2 ,4-trimethylbenzene ,tribromomethane , benzene ,and toluene have the highest contents in the air. The content of the total VOCs in the ambient air in He dong District is higher than that in Hexi District . The main sourcesof VOCs may be the oil chemical plants ,vehicle exhaust and Maoming Refinery .