Two triarylamine-containing flexible polybenzoxazine films with Tg up to 312 °C were prepared by the thermally induced curing reaction of the corresponding polybenzoxazine precursors, which were synthesized by the reaction of paraformaldehyde with bisphenol A and 4,4′-diamino-4′′-methoxytriphenylamine (1) or N,N′-bis(4-aminophenyl)-N,N′-di(4-methoxyphenyl)-1,4-phenylenediamine (2). By introduction of triarylamine units into the polybenzoxazine precursors, the resulting solution-processable polybenzoxazine precursor films not only exhibited interesting multi-colored electrochromic behavior with a high contrast ratio both in the visible range and near infrared region (NIR) but also could effectively increase the oxidation stages when compared with their corresponding polyamides.