This preliminary study was conducted to modify the surface of the fiber to enhance chitosan interaction using silence coupling agent. The OPF modified with bis-aminosilane was characterized on the water absorption behaviour from 24 to 168-hour immersion time. The result indicated that the composite treated with bis-(trimethoxysilylpropyl) amine absorbed the least water compared to the composite without silane treatment. The Tensile test indicated that the bis-aminosilane improved the tensile strength. The SEM micrograph showed chitosan was not pulled out from the fiber surface after 168-hour immersion time and the presence of bis-aminosilane enhance the adhesion between fiber/chitosan polymer matrix.