Polypropylene/wood flour composites with different nanoclay and maleic anhydride grafted polypropylene (PP-g-MA) contents were fabricated by melt compounding and then by injection molding. The mechanical properties, such as flexural modulus, tensile modulus, elongation at break, and impact strength, were evaluated. Results indicated that the flexural modulus, tensile modulus, and elongation at break increases with increase of nanoclay up to 3 phc at the same concentration of PP-g-MA, and then decreases. However, the impact strength of the composites decreases with increased nanoclay loading. Also, the effect of compatibilzer was positive in terms of enhancing the mechanical properties of the composites. The morphology of the nanocomposites has been examined by using X-ray diffraction and transmission electron microscopy. Morphological findings revealed that intercalation form, the sample with 3 phc concentration of clay, which implies the formation of the intercalation morphology and better dispersion than 6 phc, and the d-spacing of clay layers in the composite were improved in the presence of compatibilizer.