Novel SiC/SiO2 bead-string like core-shell nanochains have been fabricated via a thermal chemical vapor deposition process without using any catalysts and templates. These SiC/SiO2 bead-string like core-shell nanochains are made up of SiO2 spheres as beads and SiC/SiO2 core-shell nanowires as strings, respectively. A Vapor-Solid growth mechanism is proposed to explain the formation of these SiC/SiO2 hetero-nanostructures in the absence of catalysts on the basis of the characterization results, the possible reactions among the solid phases, intermediate gas phases and surface energy minimization. Moreover, these SiO2-SiC bead-string like nanochains exhibit good hydrophobicity with a water contact angle over 140 degrees, which is caused by the special surface composition. This hydrophobicity makes these SiO2-SiC bead-string like nanochains promising candidates as surface protective or self-cleaning materials in harsh environments.