The mechanical properties and the surface property of wood flour/continuous glass mat/polypropylene composites have been investigated. The suitability of wood flour as a filler for continuous glass mat-reinforced polypropylene has been tested using different mesh sizes (e.g., 20 and 40 mesh), as well as by varying the weight percentage of wood flour from 0%-30%. Moreover, different treatments such as coupling agent A-1100 and functionalized polypropylene grafting with maleic anhydride, and so forth, have also been used to improve the compatibility of wood flour and glass fiber with the polymer resin. In addition, the effects of the surface weight of glass mat and matrix resin have been studied. The extent of the improvement in mechanical properties depends on the wood flour content and size, the surface weight of the glass mat, the matrix resin, and the surface treatment of wood flour. After adding wood flour, the contact angle of distilled water on the composite surface decreases and the polar component of surface tension increases.