In this study, the influence of filler shape and filler content on the physical and mechanical properties of silicon carbide/epoxy nanocomposites was investigated using silicon carbide nanoparticles and nanowhiskers. Samples containing 0.5, 1, 2 and 4 wt% of β-silicon carbide nanowhiskers and nanoparticles in epoxy resin were prepared using a high-intensity ultrasonic liquid processor and casting technique. Mechanical and physical tests such as tensile, flexural, hardness, and wear along with a morphological investigation by FT-IR, scanning electron microscopy and transition electron microscopy were performed. Results of mechanical tests indicating about 20% and 40% improvement were achieved in nanoparticle (1 wt%) and nanowhisker (2 wt%) reinforced samples, respectively. Also mechanical experiment results have been evaluated with theoretical models. Tribological results show that wear and frictional properties improved about 50% and 30%, respectively, by adding silicon carbide nanoparticles (4 wt%) and nanowhiskers (4 wt%) to epoxy resin. TEM and SEM observations showed that nano-fillers are dispersed in low weight ratio but agglomerated above a critical content.