PURPOSE: To provide the titled compsn. which gives moldings having an excellent electromagnetic wave shielding effect and excellent mechanical strength, consisting of a thermoplastic resin and a metallic short fiber having a specified length and a specified diameter produced by chattering cutting method.

CONSTITUTION: A metallic short fiber (e.g. brass fiber) which has a length of 0.1W3mm and in which diameter distribution is normal distribution, an average diameter is 20W90μ and standard deviation, σ is 10<σ<30, produced by chattering cutting method, is mixed with a thermoplastic resin (e.g. propylene resin) in a weight ratio of 3W7:7W3. If desired, 5W100pts.wt. (based on the quantity of the thermoplastic resin) filler (e.g. CaCO3), lubricant, coupling agent, flow improver, etc. are added thereto. Since said short fiber is well-dispersible in the thermoplastic resin, a molding of a uniform quality can be easily obtd. and the resulting moldings have an excellent electromagnetic wave shielding effect, even when a small amount of the metallic short fiber is incorporated therein.