Natural rubber (collected in latex form) as a basic materials in tire manufacturing has its own weakness which is its mechanical properties. The shifting from petroleum-based material to renewable material as the potential solution to overcome the limitation of natural rubber, has accelerated the development of renewable material, especially biomass. Starch which has suitable acoustic properties, good tensile strength, and also density regarding its chain molecule structure and its porous structure is an interesting filler material in natural rubber to improve the mechanical properties of tyre products. However, both materials have a different polarity making them not compatible towards each other, where starch and natural rubber are polar and non-polar, respectively. Functionalization of natural rubber through grafting starch onto it is a promising technique to provide a compatibilizing product hybrid as one of raw materials in the manufacture. Glow Discharge Electrolysis Plasma (GDEP) is a prospective method to the grafting through forming unstable species such as free radical, cation and anion, to initiate the reaction. In this study, the feasibility of grafting starch on natural rubber were investigated. The effect of discharge time (5, 10, and 15 min) and discharge voltage (612.9, 658.3, and 703.7 V) on the efficiency of natural rubber hybrid formation were studied. The experiments successfully indicated a product obtained from the grafting, as an ether bond at 1554 cm-1 in FTIR spectra. Furthermore the sessile drop testing implied a polarity decreasing of the starch. Based on the product yield calculation and the sessile drop testing, the optimum discharge time and discharge voltage were obtained at 10 min and 658,3 V, respectively.