TiO2 coating on Si3N4-based materials powders (Si3N4, α-Y-sialon, β-sialon) was accomplished by heating the powder suspension containing the precursor (1.0 vol% H2O + Ti(O-i-C3H7)4) from 15 to 40 °C. The success of homogenous coating was confirmed by TEM observation. TiO2 coated on the powder is nitrided with NH3 gas at 800 oC to TiN with uniform particle size 10–20 nm. Spark plasma sintering of composite TiN/ Si3N4-based particles at 1400 - 1600 °C yielded the composite ceramics with a relative density > 96% without sintering additives. Sintered TiN/ Si3N4-based composite ceramics containing 17.5 - 25 vol.% TiN showed a higher electrical conductivity > 103 −1 cm-1, enabling these ceramics to be suitable for electric discharge machining.