TiCN-based cermets with varied fractions of Si₃N₄nanopowder (0–5 wt.%) were prepared by spark plasma sintering. The microstructural and mechanical properties of these cermets were investigated. In general, with increasing addition amount of Si₃N₄nanopowder the relative density as well as mechanical properties of the as-prepared TiCN cermets increased first and then decreased. The samples containing 2 wt.% Si₃N₄nanopowder presented the best performance with the relative density of about 98%, bending strength of 1000 MPa, and Vickers microhardness of about 1810 HV₁₀.