In this paper, the TiCN-based cermets were fabricated with ultrafine TiCN, metal binders and carbide additives. Different content of C and Al were separately added to eliminate the oxygen contamination. The composition of the mixture was TiCN-10Mo-20WC- 20Ni-xC/Al. Effect of the C and Al addition on microstructure and mechanical properties was investigated. Results indicated that cermets with carbon addition had higher relative density and more homogenous microstructure while the Al addition had the opposite effect. Proper addition of carbon improved the mechanical properties.