In this work, a blend of styrene-butadiene rubber (SBR) filled with wool fiber (WF) was successfully prepared through compression molding using tetramethyl thiuram disulfide (TMTD) as a catalyst. The WF mixing to SBR with the proportion varying from 25 to 150 phr concerning the total weight of SBR. The effect of adding WF on the mechanical properties was examined. Also, the morphology and chemical structure properties were examined by used a scanning microscope (SEM) and Fourier infrared (FTIR), respectively. The results showed that the tensile strength and the elongation at the breaking stage are gradually reduced with the adding of WF. This may be due to WF are blended with the rubber randomly. The SEM images of WF/SBR blends showed some voids in the SBR matrix and weak adhesion between WF and SBR interface. The FTIR results revealed that the reaction of WF with the SBR matrix occurred to confirm the WF grafting SBR.