Polyacrylonitrile was grafted onto kenaf fibers in aqueous media by eerie ion-p-xylene redox system. The graft yield dependence on p-xylene concentration in the range 1.8-45.0 x 10(-4) M showed a minimum accompanied by an enhanced yield. This suggested the existence of two kinetically distinct grafting reactions associated with two precursor-initiating species, a p-xylyl radical and a diradical. The frequency of graft F-g and the average molecular weight of grafted polymer M-v were inversely related at varying concentrations of p-xylene with values for M-v of up to 5.18 x 10(4). The effect of eerie ion concentration on M-v showed that the ion is nonterminating at low concentrations in the range 8.3-33.3 x 10(-3) M. The graft yield showed positive temperature dependence in the region of 30-40 degrees C and a negative one at higher temperatures, resulting in a decrease in the initial rate of graft at 70 degrees C by a factor of 8 compared to its value at 40 degrees C.