Monodispersed electroconductive particles were prepared by nitriding composite particles. The composite particles were monodispersed silica particles coated uniformly with a titania layer. The composite was obtained by hydrolysis of titanium isopropoxide in the presence of silica seed particles synthesized by hydrolysis of tetraethyl orthosilicate. The nitriding experiments of composite particles were conducted in a tube furnace at various temperatures and constant flow rate of ammonia gas. Xray diffraction patterns of the composite particles after nitriding revealed that titanium nitride was produced at temperature higher than 973 K. From scanning electron micrographs, it was found that composite particles after nitriding are maintained as monodispersed forms of seed particles. The electroconductivity of the composite particles after nitriding is high enough for practical usage.