The curing and pyrolysis of hydrogen-containing polysiloxane (PSO) and divinylbenzene (DVB) were investigated in this paper. It was found that H2PtCl6 was an effective catalyst for the curing of DVB/PSO. The mass ratio of DVB/PSO had great effect on ceramic yield. The cured DVB/PSO with a mass ratio of 0.5:1 had the highest ceramic yield (76%) at temperature up to 1000degreesC, and its pyrolysates consisted of 38.3 wt% silicon, 27.4 wt% oxygen, and 34.3 wt% carbon of which 26.3 wt% was free carbon. The composition and structure of pyrolysates of DVB/PSO were changed with increasing pyrolysis temperature. The pyrolysis behavior of DVB/PSO was characterized by thermal analysis. DVB/PSO-derived Si-O-C composites reinforced with carbon fiber cloth (C-f/Si-O-C) were fabricated. The results showed that the flexural strength of Cf/Si-O-C composites could be increased from 118.00 +/-5.00 MPa to 139.78 +/- 7.68 MPa if the pyrolysis temperature was elevated from 1000 to 1400degreesC, which was ascribed to the weakened interfacial bonding. (C) 2005 Springer Science + Business Media, Inc.