The present invention is a polyamide resin composition having excellent thermal aging resistance and excellent mechanical characteristics, and containing 0.5 to 20 part(s) by mass of a metal cyanide salt having the general composition formula (Ax[M(CN)y]) to 100 parts by mass of a polyamide resin. In the general composition formula, M is at least one member of transition metal elements in groups 5 to 10 and periods 4 to 6 of a periodic table; A is at least one member of alkali metal and alkaline earth metal; y is an integer of from 3 to 6; and x is a number calculated by (y−m)/a, wherein m is a valence of M and a is a valence of A.