PURPOSE: To make it possible to efficiently produce forming material, in the matrix of which 100% oriented cut fibers indispensable for the forming of three- dimensional matter are present, by a method wherein inorganic fiber tow-like matter is cut under the condition that sheet-like aggregate, which is produced from film or tow-like thermoplastic resin material and substantially non-twisted inorganic fiber tow-like matter, is under tension.

CONSTITUTION: Both substantially non-twisted reinforcing fiber tow 1 and thermoplastic fiber tow 2, for example, obtained from thermoplastic resin for matrix are uniformized in tension, separated into single filaments and preferably mixed with each other and, after that, fed to a feed roll 3. The roll 3 nips well a sheet-like aggregate consisting of the tows 1 and 2. Draft is given to the sheet-like aggregate by the feed roll 3 and a delivery roll 4 so as to continuously cut off the reinforcing fiber tow by properly selecting said draft. The major part of the fiber tow for matrix reaches the roll 4 without being cut off. In said fiber tow for matrix, the cut-off inorganic reinforcing fibers are oriented and scattered in the longitudinal direction of the fiber tow for matrix.