A new class of benzoxazine polymers were synthesised from bis(4-amino-3-hydroxymethylphenyl)methane with substituted phthalic acids by solution poly-condensation in polyphosphoric acid. The model compound bis(4H-3,1-benzoxazine)2,2′-p-phenylene was also synthesised. The polymere were characterised by UV and IR spectra, viscosity measurements and thermal analysis. © 1980 Springer-Verlag.