To obtain the subject composition capable of providing a molding product excellent in impact resistance and processing fluidity and free from delamination by compounding a polycarbonate resin, etc., with a styrene-based resin, etc., and a copolymer containing a specific formamide group.

This resin composition is obtained by compounding (A) 10-90 pts.wt. at least one kind of resin of a polycarbonate resin, a polyamide resin, a polyester resin, etc., with (B) 10-90 pts.wt. at least either one resin in a styrene-based resin and a polyphenylene ether resin, (C) a copolymer of a formamide group-containing monomer (e.g. styrene) represented by the formula (R1 to R6 are each H, a 1-8C alkyl, a 6-10C cycloalkyl or a 6-10C arylalkyl) in an amount of 0.05-20 pts.wt. based on 100 pts.wt. resin composition comprising the components A and B. The resin composition is excellent in impact resistance and processing fluidity and has good appearance and causes no delamination when molded and processed.