Inorganic-organic boron-silicon-acetylene hybrid polymer (PABS) was prepared by the polycondensation reaction between phenylboric acid and diphenyldichlorosilane and then terminated by phenylacetylene. The structure was characterized by using FTIR, C-13-NMR, H-1-NMR, and GPC. PABS was a kind of resin exhibited high viscous at room temperature and good solubility in common organic solvents. The thermal and oxidative properties were evaluated by DSC and TGA. Exothermal peak at 370 degrees C observed by DSC was attributed to reaction of the acetylene units. PABS showed excellent thermal and oxidative stability, and TGA exhibited the temperature of 5% weight loss (Td(5)) was 625 degrees C and char yield at 900 degrees C was 90.0% in nitrogen. Surprisingly, both Td(5) and char yield at 900 degrees C showed slightly increase in air, which was 638 degrees C and 90.9%, respectively. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 47-52, 2011