An epoxy-group-containing monomer, glycidyl methacrylate (GMA), was grafted onto poly(vinylidene fluoride) powder via preirradiation-induced emulsion graft polymerization. The existence of graft chains was proven by chemical structure characterization with Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis. The degree of grafting was calculated by means of fluorine content analysis. A kinetic study indicated that, with the emulsion graft polymerization system, the GMA conversion rate was high, exceeding 80%. The variation in the molecular weight of the grafted polymer was measured by gel permeation chromatography, and its crystallinity was investigated with differential scanning calorimetry. The epoxy groups in graft chains were found to be suitable for further chemical modification. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 3575-3581, 2010