The aim of the present work is to study the oxidation reactions between an aromatic hydrocarbon, toluene and oxygen. Experiments have been performed in a low-pressure plasma tubular reactor supplied by an RF 13.56 MHz generator. On-line mass spectrometry and off-line gas chromatography were used for a qualitative and quantitative analysis of the effluents. The reaction can lead to the formation of products in the solid (deposited on the wall of the reactor), liquid or gas state. Hydrocarbons (benzene, ethylbenzene, diphenylethane), as well as oxygenated species resulting from competition between the oxidation of the aromatic ring (phenol, cresols) and the oxidation of the alkyl side chain (benzyl alcohol, benzaldehyde), can be obtained. The power and the amount of added oxygen were studied by comparing the mass spectrometry and gas chromatography results. Reaction mechanisms are discussed.