A polyamide resin composition containing a polyimide resin (A), a modified styrene-based copolymer (B), a modified high-density polyethylene (C), and an aliphatic metal salt (D), and having a melt mass flow rate (MFR) of 20 g/10 minutes or more and less than 60 g/10 minutes and a 65% RH equilibrium water absorption rate of less than 3%. The polyamide resin composition can form a molded article having a sufficiently high limit of fatigue against continuous load, achieve high mechanical characteristics and high fluidity to prevent the occurrence of a short shot or decrease in the strength of a welded part even in a large and/or thick molded article, and has excellent mold releasability and more excellent abrasion resistance than ever before.