One of the key issues for the development of high toughness carbon nanotube (CNT) reinforced composites is the control of the interfacial bond between the CNT and the matrix. Here, we introduce a novel technique to facilitate the homogeneous coating of single-walled carbon nanotube (SWCNT) bundles with polycarbosilane (PCS)-derived SiC nanoparticles. The PCS dissolved in n-hexane was used as a precursor for SiC nanoparticles. The results obtained from XRD, TEM and EDXS analyses confirmed the formation of β-SiC nanoparticles of about 20 nm in diameter, which possessed a relatively homogeneous distribution on the SWCNT bundles. It was shown that the number of SiC nanoparticles per unit of SWCNT surface area could be adjusted by changing the weight ratio of PCS and SWCNTs. This approach may provide a useful route for the preparation of SiC/SWCNT nanocomposites that have a tunable interface property with the matrix and potentially with an enhanced anchor effect, which may have potential applications as a reinforcing element in CNT/ceramic composites.