||Polylactic acid (PLA) is an eco-friend and biodegradable polymer. However, due to the brittleness of PLA, there are limitations in applying it to various flexible packaging industries. Therefore, PLA often blended with other ductile polymers such as poly (butylene adipate-co-terephthalate) (PBAT). In this study, PLA/PBAT blends with various contents were prepared by melt mixing technique. We have identified the composition of the PLA/PBAT blend with optimal mechanical properties and prepared nanocomposites by adding cellulose nanofibers (CNF) to reinforce PLA/PBAT blends. The morphological results through scanning electron microscopy (SEM) showed that PLA/PBAT blend is immiscible and CNF has a good affinity to the PBAT phase due to an interfacial tension of polymer and CNF. It was also confirmed that the PLA/PBAT blend improved the mechanical and barrier properties due to CNF indicating that the nanocomposite could be tailored for proper application, especially in packaging field.