In this article, two kinds of methods for grafting polyglycidyl methacrylate (PGMA) onto Al2O3 surface by the radical polymerization initiated by peroxide groups and double bond groups,respectively, were. investigated. In the first method, peroxide groups, as initiators, were immobilized onto the Al2O3, surface. Then, GMA was polymerized on Al2O3 under the radicals decomposed by peroxide groups, and PGMA was grafted onto Al2O3 it in the second method, 3-methacryloyl-propyl trimethoxysilane was chemically bonded onto the Al2O3 surfaces firstly to introduce double bonds. Secondly, the copolymerizations between the immobilized double bonds and the monomer GMA were performed, homopolymerizations of GMA followed, and finally PGMA was grafted to the Al2O3 surfaces. The effects of grafting methods on grafting degree were examined mainly. At the same time, the effects of different grafting conditions on the grafting,degree were researched. I:Furthermore, the effect of the grafted particles; PGMA/Al2O3 on impact strength of the epoxy Composites was studied. It was found that the grafting degree achieved by the first method was much higher than that by the second, and the grafting degree can reach about 54% Moreover, the impact strength of epoxy composites containing PGMA/Al2O3 particles were improved largely, and which increased with the grafting degree. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 41-48, 2009