Improvement in properties of natural rubber can be done by several methods. In this research, gamma radiation technique, which is simple, accurate, easy to control and clean, was applied to enhance the properties of natural rubber (NR) in latex state. The purpose of this research is to study the appropriate condition for preparing grafted natural rubber latex by using irradiation method. Vinyl acetate monomers (VAc) were grafted onto natural rubber latex (NR-g-PVAc) and irradiated at 0-10 kGy by gamma radiation from Cobalt-60 source at room temperature. Here, the sequence of grafting and crosslinking steps including radiation grafting after crosslinking (NRXVAc), radiation grafting without crosslinking (NRG) and radiation grafting and crosslinking in one step (NRGX) were considered. Physical properties of grafted natural rubber such as chloroform number, swelling ratio and gel content were measured. The VAc content of NR-g-PVAc was investigated by titration and visualized by FTIR spectroscopy. The FTIR spectra of NR-g-PVAc prepared at 4 kGy both after crosslinking and without crosslinking showed a characteristic peak of the vinyl acetate group at 1734.91 and 1735.36 cm-1 corresponding to the C=O stretching and the absorption peak at 1226.95 and 1224.94 cm-1 were due to the C-O stretching. It was confirmed that VAc could be grafted onto natural rubber molecular chains effectively under appropriate irradiation conditions. From the result, radiation grafting was found to be a useful technique for grafting of vinyl acetate onto natural rubber.