Nitrile-butadiene rubber (NBR) composites incorporated with four kinds of rice bran carbon (RBC), with different particle sizes, were fabricated by latex compounding method based on the superior dispersion ability of RBCs in NBR latex. Field emission scanning electron microscopy was employed to confirm the uniform dispersion of filler in the matrix. The mechanical property and oxygen transmission rates of the vulcanizates were studied. The RBC with smallest particle size exhibited best reinforcing performance. Then RBC/NBR composites, with different concentration of (3-mercaptopropyl) trimethoxysilane (MPTMS), were prepared by a facile process. MPTMS, for the purpose of enhancing the compatibility between the filler and matrix, was incorporated into the rubber by an in situ method. Morphological analysis, Raman spectroscopy, and dynamic mechanical analysis tests confirmed the improvement of the interfacial interactions between the RBC and NBR matrix. The incorporation of MPTMS significantly enhanced the mechanical and oxygen barrier properties of the RBC/NBR composites. Both, the mechanical property and oxygen barrier abilities increased as the loading of the MPTMS increased, within a range of 0-9 phr. POLYM. COMPOS., 2016.