PURPOSE: To produce the composition useful as the reinforcement for resin, rubber, cement, etc,. under an improved working environment and workability by adding a soln. contg. epoxy resin to carbon fiber, cutting or chopping the wetted fiber into a lumpy material and then carbonizing the material.

CONSTITUTION: The carbon fiber to be treated is dipped in the soln., dispersion, etc., of a coupling agent, or the soln., dispersion, etc., are sprayed on the fiber to impregnate the fiber with a processing soln. The impregnated fiber is compressed by a roller, etc., to remove the excess soln. and to increase the bulk density, and then the wetted compressed body contg. the coupling agent is cut or chopped to specified size to form a small lumpy material. The lumpy material thus obtained is carbonized by heating at about 900-1200°C in a nonoxidizing atmosphere to obtain the desired carbon-fiber lumpy composition.