The grafting of maleic anhydride (MA) onto natural rubber latex (NR) has received wide attention as it could extend applications of natural rubber to wider applications. In the past, grafting of m aleic anhydride onto natural rubber latex has been carried out by chemical method, which uses large amount of chemicals, energy and generated large amount of waste. Recently, irradiation method has been used for several purposes including vulcanization of natural rubber latex and grafting with some monomers. Therefore, it is of interest to investigate on grafting of maleic anhydride onto natural rubber latex by irradiation technique. In this study, the effectiveness of grafting natural rubber latex with maleic anhydride was investigated by exposing to cobalt-60 gamma irradiation at various radiation doses ranging from 0-10 kGy and various concentration of maleic anhydride (1, 3, 5, 7, 9 phr). Careful stabilization of natural rubber latex in the presence maleic anhydride before irradiation is an important step in achieving high grafting efficiency. The FTIR spectra (Fourier transform infrared spectrometer), 1H NMR spectra (Proton nuclear magnetic resonance) and gel content analysis have confirmed the efficiency of grafting polymerization of maleic anhydride onto natural rubber in the latex. Keywords: Radiation grafting, Maleic anhydride, Natural rubber