Two series of benzoxazine (BOZ) based composites were prepared with graphene oxide (GO) and graphite via in situ intercalative polymerization. Based on isothermal and non-isothermal mode Differential Scanning Calorimetry results, BOZ with the addition of GO could not only decrease the cure temperature, but also increase the cure rate of BOZ. On the contrary, BOZ with the addition of graphite would delay the polymerization of BOZ monomer. It was hypothesized that carboxyl groups of GO acted as weak organic acid which accelerated the ring opening procedure. Interestingly, BOZ/GO composite with 1 wt% GO occupied the least time to form polymer networks, attributing to the catalytic effect and good dispersion of GO. Moreover, BOZ with 1 wt% content of GO had relatively higher glass transition temperature and char yield than those of the corresponding BOZ/graphite sample, which was due to relatively stronger intermolecular interactions between GO and BOZ. (c) 2013 Elsevier Ltd. All rights reserved.