Coating formation on multi-walled carbon nanotubes (MWCNTs) treated in a coke bed in the temperature range of 1000~1500 °C using silicon powder (Si) and the mixture of aluminum and silicon powders (Al+Si) as the silicon sources and its oxidation resistance were investigated by means of X-ray diffraction, high resolution transmission electron microscopy equipped with energy dispersive X-ray spectroscopy and thermogravimetric analysis-differential scanning calorimetry. Results show that using Si as a silicon source, SiC coating forms on the surface of MWCNTs after treated below 1400 °C. At 1500 °C, most of MWCNTs have transformed into solid SiC nanowires. Using Al+Si as a silicon source, the thickness of the coating increases at the same treated temperature compared with Si source. In addition, transformation of MWCNTs is prevented after treated at 1500 °C. The oxidation resistance of the treated MWCNTs improves compared with the as-received ones, and it gets better with increasing the thickness of the coating. Non-isothermal kinetics shows that oxidation activation energy of the as-received MWCNTs is 157.69 kJ/mol, while they are 202.39 kJ/mol and 230.70 kJ/mol after MWCNTs treated at 1400 °C using Si and Al+Si as the silicon sources, respectively