Short-carbon-fibers (C_sf) reinforced Ti₃SiC₂ matrix composites (C_sf/Ti₃SiC₂, the C_sf content was 0 vol%, 2 vol%, 5 vol%, and 10 vol%) were fabricated by spark plasma sintering (SPS) using Ti₃SiC₂ powders and C_sf as starting materials at 1300 ℃. The effects of C_sf addition on the phase compositions, microstructures, and mechanical properties (including hardness, flexural strength (σ_f), and K_IC) of C_sf/Ti₃SiC₂ composites were investigated. The C_sf, with bi-layered transition layers, i.e., TiC and SiC layers, were homogeneously distributed in the as-prepared C_sf/Ti₃SiC₂ composites. With the increase of C_sf content, the K_IC of C_sf/Ti₃SiC₂ composites increased, but the σ_f decreased, and the Vickers hardness decreased initially and then increased steadily when the C_sf content was higher than 2 vol%. These changed performances (hardness, σ_f, and K_IC) could be attributed to the introduction of C_sf and the formation of stronger interfacial phases.