PURPOSE: To form a molded product having appearance of a natural stone by selecting a mixing ratio of a colored or colorless thermoplastic resin matrix and at least two colored or colorless fillers of a natural fiber, a carbon fiber and a mineral different in dimension, a particle size and a color to perform processing.

CONSTITUTION: Fibers with a length of 1-1.9 mm different in dimension such as sawdust, natural fibers with a length of 2-5 mm different in dimension and a mineral raw material having the min. size such as mica are mixed with a thermoplastic resin matrix of an acrylic resin as a filler. The natural fibers are variously colored. The compsn. of the resin matrix and the filler is brought to a molten state and processed by allowing one stage performing the mixing operation of the whole or a part containing one fraction of a thermoplastic resin to precede to obtain a molded product having appearance of a natural stone.