Abstract: Short carbon fiber reinforced pitch-based carbon/carbon composites (SCFRC) with high density and low cost were fabricated by mold pressing followed by semi-carbonization. The effect of the volume fraction of short carbon fibers on density and mechanical properties of the SCFRC was studied. Their microstructures and fracture morphologies were observed using an optical microscope and SEM, and the reinforcing mechanism of the short carbon fibers was elucidated. Results show that mechanical properties increase linearly with an increase of short carbon fiber volume fraction from 0% to 11.8%, and the strengthening mechanisms involved are based mainly on crack deflection, fiber bridging, fiber debonding and pull-out.