Ti(C,N) solid solution were prepared at 1450°C and 1atm nitrogen pressure and the effect of the ways of adding nitrogen on the mechanical properties and microstructures of Ti(C,N)-based cermets were investigated. XRD and FESEM were employed to characterize the as-prepared Ti(C,N)-based cermets. Vickers hardness and fracture toughness were also tested. As a result, The mechanical properties of Ti(C,N)-based cermets prepared by Ti(C,N) solid solution is better than that directly prepared by TiN. The former shows the homogeneous microstructures, the same particle size of hard phases, low porosity, and good sintering character, due to the significant reducing of denitrification when using Ti(C,N) solid solution to introduce nitrogen element. The cross-section SEM images reveal that the dominant fracture behavior of Ti(C,N)-based cermets is transgranular fracture, also including intergranular rupture. The presence of Ni3Ti brittle phase will affect the fracture toughness property of the as-prepared cermets. The more the content of Ni3Ti is, the lower KIC is.