A novel acetylene- and maleimide-terminated benzoxazine, 3-(3-ethynylphenyl)-3,4-dihydro-2H-6-(N-maleimido)-1,3-benzoxazine (MBZ-apa), was successfully synthesized with N-(4-hydroxyphenyl)maleimide, paraformaldehyde, and 3-aminophenylacetylene. The structure of the benzoxazine is confirmed by FTIR and H-1-NMR spectroscopies. MBZ-apa is easily dissolved in common organic solvents. Differential scanning calorimetry (DSC) was used to study thermal cross-linking behavior of MBZ-apa. The DSC curve shows only a single exothermic peak due to the oxazine ring-opening polymerization and the polymerization of the acetylene and maleimide groups occurring simultaneously in the same temperature range. Dynamic mechanical analyses (DMA) reveals that the novel polybenzoxazine exhibits high glass-transition temperature (T-g) (ca. 348 degrees C). The storage modulus arrives at 4.5 GPa in the range of room temperature to 330 degrees C. The polybenzoxazine exhibits good thermal stability as evidenced by thermogravimetric analysis (TGA). Pyrolysis-gas chromatography/mass spectrometry (Pyrolysis-GC/MS) was employed to characterize the polybenzoxazine. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 340-346, 2013