The evolution of rim structures during the liquid-phase sintering of Ti(C0.7N0.3)(.)xWC(.)20Ni (x = 5-25 wt%) was investigated under a variety of sintering conditions and densification procedures. In addition, the onset of formation of the surrounding structures in the system was examined by analyzing the microstructures and rim compositions. The compositions of the inner and outer rims were found to vary with sintering temperature and holding time. The results indicate that the inner rim forms at sintering temperature and the outer rim forms thereafter during the sintering or cooling stage of sintering. The coalescence of Ti(C,N) appears to occur at the sintering temperature to a great extent before the formation of the rim phases.