A resin composition which contains an aluminum pigment and, despite this, shows excellent weatherability. The aluminum pigment-containing resin composition comprises a methacrylic resin comprising 100 parts by weight of a polyolefin resin and 0.5-10 parts by weight of an aluminum pigment and, incorporated therein, 0.001-10 parts by weight of a hindered amine compound represented by the general formula (I) (wherein R1 is hydrogen, hydroxy, alkyl, hydroxyalkyl, alkoxy, hydroxyalkoxy, or an oxy radical and R2 is alkyl or alkenyl) and 0.001-10 parts by weight of a benzoate compound represented by the general formula (II) (wherein R3 and R4 each independently is hydrogen, alkyl, or arylalkyl and R5 is alkyl).