In this study, the polylactic acid (PLA)/banana fiber (BF) composites were prepared by the melt blending method.Moreover, BF would be conjugated onto PLA chains via coupling agent and chemical modification.Consequently, the thermal stability and mechanical properties of PLA can be dramatically elevated with the incorporation of BF.Mechanical tests showed that the tensile strength of the composites markedly increased with the fiber content, reaching 78.6 MPa in the case of being reinforced with 40 phr fiber, which is about 2 times as compared to the pristine PLA.