The incompatible thermoplastic poly lactic acid/carboxylated acrylonitrile butadiene rubber (PLA/XNBR) was prepared, and the effect of graphene oxide (GO) as a reinforcement and glycidyl methacrylate (GMA)-grafted XNBR (XNBR-g-GMA) as a compatibilizer on the properties of PLA/XNBR blend was investigated in this research.The microstructure, mech. behavior, thermal, rheol., and dynamic mech. properties of PLA/XNBR composites were investigated by field emission SEM (FESEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), tensile test, and dynamic mech. thermal anal. (DMTA).The incorporation of XNBR-g-GMA improved the compatibility of the PLA/XNBR blend phases, as confirmed by microstructure and DMTA anal.The results of the mech. properties showed that with an increase in GO content in the PLA/XNBR/XNBR-g-GMA matrix, there was a significant improvement in tensile strength, Young′s modulus, hardness, and impact strength.In order to validate the exptl. mech. and rheol. results, various theor. models were applied and a good agreement was observed between the theor. and exptl. data.