Abstract: This is a vibratory diaphragm for a loudspeaker of sound appliances such as stereophonic phonographs or television receivers, which is made of composite material composed of polyimide resin, graphite granules and fabric of high strength and high modulus filaments. A vibratory diaphragm having well-balanced characteristics in the specific modulus, the internal loss, the mechanical strength, the thermal stability and the fatigue resistance is obtained. The polyimide resin gives high thermal stability, while the graphite granules greatly increase the internal loss. The fabric of high strength and high modulus filaments improves the specific modulus, the mechanical strength and the fatigue resistance.