In situ synthesis of ultra-long SiC-SiO2 nanowires were successfully conducted with the raw materials of silicon and phenolic resin by an effective and catalyst-free technique. Several millimeters long SiC-SiO2 nanowires with the diameters in the range of 50-200 nm were mainly composed of Si, C and a small amount of O, and the formation of several millimeters long SiC-SiO2 nanowires was attributed to a low flow rate and carbon sources supplied continuously by the pyrolysis of phenolic resin. A catalyst-free vapor-solid (VS) growth mechanism was proposed to illustrate the growth process of ultra-long SiC-SiO2 nanowires in present experiment, which provides a promising method for in situ fabrication of SiC-SiO2 nanowires as reinforcements into composites. (C) 2016 Elsevier B.V. All rights reserved.