A novel silicon-containing resin (ESA resin) was successfully synthesized by the condensation reaction of lithium arylacetylide with chlorosilane in high yields. The resin was characterized by the techniques of FTIR, Si-29-NMR, and gel permeation chromatography. Thermal cure process was monitored by DSC and FTIR methods. This resin could melt at around 100 degrees C and thermally cured at 200-250 degrees C with low exothermal enthalpy. Owing to the high aryl groups containing and the complete crosslinking of ethynyl groups, the cured ESA resin exhibited excellent thermal stability and high char yield. The decomposition temperature T-d5 of the cured resin was at 510 degrees C, and the residue yield at 900 degrees C was 82.9% in N-2. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 714-719, 2010