The effect of fiber orientation angle of composite materials on the gear tooth root stresses is analytically investigated in order to select the required orientation of the fibers inside the gear tooth. which leads to improve the gear tooth strength. The effect of geometrical parameters (loaded or unloaded pressure angles, number of teeth, radius of fillet and profile correction) and type of fibers glass, graphite and boron) are also studied. A stress analysis using the finite element method is performed for reinforced gear subject to bending loads. The results indicate that there is an effect of the fiber orientation on the root stresses of the gear tooth, and also, there is a direct proportionality between the improving of the gear strength with geometrical parameters