PURPOSE: To provide a composite material compsn. for wet-process friction material, whish has a stable and high coefficient of friction, by mixing a soft, porous amorphous particle or fiber, carbon black, a vulcanizing agent, additives, etc. with a matrix composed of a fluoroelastomer.

CONSTITUTION: 20W70pts.wt. fluoroelastomer (A) (e.g. a tetrafluoroethylene/ propylene copolymer), 1W20pts.wt. org. or inorg. porous amorphous particle or fiber (B) (e.g. cork powder) having softness at least equal to that of component A, 10W50pts.wt. carbon black (C) and 3W10pts.wt. vulcanizing agent and additives (D) (e.g. vulcanization accelerator, antioxidant) are mixed together to obtain the desired compsn. for wet-process friction material. When the compsn. is used as a friction material in a wet process, oil is occluded in the voids of component B so that when the material is pressed against an opposing surface, a thin oil film is formed on a frictional surface and hence, a consistent coefficient of friction can be obtained.