The upper arm of the suspension system within a light weight vehicle, in theory, primarily helps to stabilize functional performances while it is in operation. However, the very part of the suspension system, in practice, proves to be effective in minimizing the horizontal shaking of body. Along with technology advances, the needs for lighter body weight, higher hopes for technical standards, and stricter requirements for mechanical properties have led to the development of composite-made upper arms. In this research, the composite upper arm was fabricated from short carbon fiber reinforced nylon 66, by injection molding process. In addition, load-carrying capacity of the composite upper arm was meticulously examined as a function of fiber volume fraction. Simultaneously, displacement observations and stress measurements between the existing steel-made and the composite-made upper arms were carefully compared in static analysis. The final results clearly showed that the composite upper arms had high strength-to-weight and high stiffness-to-weight ratios.