A three-dimensionally (3D) well-ordered assembly composed of silicon oxycarbide (SiOxCy) microparticles was fabricated by an infiltration process using SiO2 inverse opal structures as molds. Polycarbosilane was used as the precursor for the SiOxCy synthesis. The effect of the viscosity of polycarbosilane solution on the morphology of the fabricated SiOxCy microparticles, and their assemblies was investigated. The ideal viscosity for the infiltration process was found to be approximately 2.0 mpa s. The structures of the SiOxCy microparticles obtained and their assemblies were analyzed by SEM, XRD, Fr-IR, and N-2 adsorption. Each SiOxCy microparticle was bonded to neighboring microparticles by bridge formation, which could enhance the mechanical strength of the prepared SiOxCy microparticle assembly. (C) 2007 Elsevier B.V. All rights reserved.