PURPOSE: To efficiently manufacture compound composition by performing both the drying of wooden fine powder and the sprinkling of the wooden fine powder over resin during a single process by a method wherein wet wooden fine powder, to which thermoplastic resin stock is added, is stirred at high speed.

CONSTITUTION: Wooden powder 2, the size of which is smaller than about 3mm or below, and polypropylene resin are blended with each other with the ratio of about 1:1 by weight, and, after being added with 0.1wt% of stabilizer of metallic soaps (calcium stearate) charged in a high speed mixer M, in order to be kneaded by high speed stirring. At this time, frictional heat is generated by the friction between wooden powder 2 and resin caused by the high speed rotation of moving blades 3 in the mixer M1 and evaporates the moisture in the wooden powder 2, resulting in bringing the wooden powder 2 into dried state. On the other hand, because the resin is softened into gum- like substance, resulting in sprinkling the wooden powder 2 over the surface of resin particles 4. After being cooled in a cooling mixer M2. The resultant wooden powder- sprinkled resin particles are extruded into a vent type extruder and fabricated into sheet by vacuum forming. The fabricated sheet is useful for interior automotive trimming material.