Graphene oxide (GO) is effective in catalyzing a wide variety of organic reactions and a few types of polymerization reactions. No radical chain polymerizations catalyzed by GO have been reported. In this article, we probe the catalytic role and acceleration effect of GO for self-initiated radical chain polymerizations of acrylic acid (AA) in the presence of GO and a preexisting polymer, poly(N-vinylpyrrolidone) (PVP), from a calorimetric perspective. Gelation experiments and DSC studies show that GO can function as a catalyst to accelerate the radical chain polymerization of AA. Isothermal polymerization kinetic data shows that the addition of GO diminishes the induction periods and increases the polymerization rates, as indicated by the much enhanced overall kinetic rate constants and lowered activation energies. The catalytic effect of GO for the polymerization of AA is attributed to the acidity of GO and the hydrogen bonding interactions between GO and monomer molecules and/or polymers.