SiC nanowires were synthesized by the infiltration process of reactive vapor Si in Ar atmosphere at 1350–1450°C, using carbonated bacterial cellulose (CBC) as carbon template and a reactant. Scanning electron microscopy (SEM), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and vector network analyzer were employed to characterize the samples. The diameter of the resulting β-SiC nanowires changes with calcination temperatures, specifically, 35–60nm for 1350°C, 40–80nm for 1400°C, and 30–60nm for 1450°C. The β-SiC nanowires obtained at 1400°C possess the highest ɛ″ of complex permittivity.