Fig. 1(a) shows the coconut shell charcoal consisted very fine granule morphology of graphite. Carbon nanopowders are obtained by vibro-milling with regular shape and have diameter less than 100 nm (Fig. 1(b)). This project will describe the results obtained in the attempt to perform rice starch-based nanocomposites, reinforced by carbon nanopowders synthesized by vibro-milling of coconut shell charcoal, which can make the rice starch polymer films with high water resistance capacity and high mechanical strength. The results of this work show that the carbon nanopowders offer the potential for improvement of mechanical properties of rice starch polymer film. By mixed 10 wt% carbon nanopowders with starch polymer film can achieve about 140% increase in the elastic modulus and 1200% increase in the tensile strength of the rice starch-carbon nanocomposite film compared to pure rice starch. Moreover, SEM was used to characterize the fracture behavior of the nanocomposite. The results attributed the improvements of these mechanical properties to a better dispersion of carbon nanopowders in starch matrix (Fig. 2(a)), and to a strong interfacial adhesion between the nanofiller and starch matrix (Fig. 2(b)). These lead to favorable stress transfer across to carbon nanopowders. The stress–strain behavior for the rice starch-carbon nanocomposite films are shown in Fig. 3. Apparently, the nanocomposite exhibits a much high strain at break at room temperature. This curve was obtained by tensile tests of sample have dimension of 1 cm wide and 0.23 cm thick using universal testing machine with gauge length of 5 cm and constant crosshead speed of 60 mm/min.