Abstract: The microstructure and properties of two plasma spraying TiCNiMo cermets coatings with different ingredient ratios are studied by XRD, SEM and energy spectrometer. It is presented that in the diffusion bonding mechanism, between hard phase and bonding phase there was a way of Mos diffusion and solid solutizing; and so the (Ti,Mo)C solid clad structure around TiC grain is formed; the bond between hard phase and bonding phase and also the bonding strength of the coatings can be strengthened by controlling properly the thickness of the clad structure.The results show that for spraying compound particles, when the ingredient ratio (wt%) of Ni and TiC is 11, the hardness and bonding strength of the coating are higher than those of the coating of which the ingredient ratio of Ni and TiC is 53.