Electrochemical methoxylation of p-xylene with methanol over mono- and multi-metal oxide(s) modified kaolin was performed under various conditions and the conversion of p-xylene was seen to be higher than 80 %. The oxidation states of the metal(s) after modification were found from catalyst characterization by powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The reaction process was monitored by UV-Vis spectroscopy and the extent of reaction was evaluated. Investigation of the application of the products by gas chromatography/mass spectrometry (GC-MS) could lead to an improvement of the octane number of gasoline.