A novel bisphthalonitrile containing benzoxazine units (BZ-BPH) was synthesized via a solventless method from 4,4'-dihydroxybiphenyl, paraformaldehyde, and 4-aminophenoxylphthalonitrile. The chemical structure of BZ-BPH was confirmed by H-1-NMR and C-13-NMR analyses. The curing behavior was investigated with DSC, FTIR, TGA, and rheology techniques. The monomer manifested a two-stage thermal polymerization pattern. The first stage was attributed to the ring-opening polymerization of benzoxazine moiety, and the second to the polymerization of phthalonitriles. Study about the effect of the catalysts including 4,4'-diaminodiphenylsulfone and FeCl3 on the polymerization of BZ-BPH was performed, and the result indicated that the addition of these agents could increase the curing rate and lower the curing temperature. Additionally, the cured product showed excellent thermal and thermo-oxidafive stability, the high char yield was 76.0% by weight at 800 degrees C in nitrogen atmosphere and 81.2% by weight at 600 degrees C in air, and temperature at 5% weight loss (T-5%) in nitrogen and air was 477.9 degrees C and 481.7 degrees C, respectively. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 1469-1475, 2010