As some new tool materials which appeared in the seventies of last century, the Ti(C, N)-based cermets have been widely used in recent years because of their good properties. The microstructure of Ti(C, N)-based cermets with various carbon contents were studied by using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffractometry(XRD). Vickers hardness and transverse rupture strength (TRS) were also measured. An increased carbon content resulted in the finer grain size, with decreased solution strength of tungsten and molybdenum in the binder phase, and a higher volume fraction of heavy (Ti, Mo, W)(C,N) cores. If the addition of carbon content was too little or too much, the phase composition of material would deviate from the normal dual phase section and lead to the formation of the third phase: η-phase if the carbon content was too low or dissociative carbon if the carbon content is too high, and the formation of the third phase would remarkably deteriorate the mechanical properties of cermets.