PURPOSE: To obtain a thermoplastic resin composition which comprises a styrene resin bearing groups reactive with epoxy and a modified olefinic polymer bearing amide and glycidyl groups, thus gives moldings of high delamination resistance and has excellent flowability and converability.

CONSTITUTION: (A) 5 to 98 pts.wt. of a styrene resin bearing functional groups reactive with epoxy, containing vinyl cyanide and/or alkyl methacrylate as copolymer components, and having a reduced viscosity of 0.2 to 1.2dl/g (in methylformamide solution, 30°C, 0.3g/dl concentration) in the fraction soluble in methyl ethyl ketone are compounded with (B) 95 to 2 pts.wt. of a modified olefinic polymer which is modified with a compound of the formula (Ar is a 6 to 23C aromatic hydrocarbon having at least one of reactive groups of glycidyl or glycidyloxy; R is H, methyl) and has an amide group and a reactive group, such as glycidyloxy and glycidyl per 2 to 1,000 olefin units to give the objective composition.