This paper covers the effect of g-radiation on crystal transformation of poly(vinylidene fluoride) before and after drawing as well as during annealing process. The results show that the drawing results in a drastic increase in both crystallinity along the meridian direction and b-form crystal content for the irradiation samples. When the drawn samples were irradiated under appropriate dose and then annealed at 140 °C, transformation from b-form to a-form was subjected to an inhibition. The transformation mechanisms between the two types of crystals are discussed on the basis of results of WAXD and DSC.