PURPOSE: To obtain a glass fiber-reinforced resin compsn. which has high tensile strength. stiffness, etc., and esp. a high impact strength by compounding a polystyrene resin with a specific glass fiber-reinforced polystyrene resin and a maleic acid-grafted resin.

CONSTITUTION: This resin compsn. comprises 35-94.5wt.% polystyrene resin, 5-60 wt.% glass fiber-reinforced polystyrene resin which is in a form of pellets comprising 20-70wt.% polystyrene resin and 80-30wt.% glass fiber and having a pellet length of 2-15 mm and a glass fiber length equal to the pellet length, and 0.5-5wt.% maleic acid-grafted resin which is obtd. by adding 0.1-10wt.% maleic acid to a mixture comprising 10-60wt.% polyphenylene oxide resin and 90-40wt.% polystyrene resin. The compsn. is useful as materials for various fans such as cooling fans, chassis of office automation apparatuses, and molded articles for electric home appliances, automobiles, etc.