A polyamide resin composition comprising 100 parts by weight of a polyamide resin and 0.005 to 1.0 part by weight of at least one compound selected from the group consisting of a metal salt of a fatty acid, a diamide compound and a diester compound. The polyamide resin is obtained by solid phase-polymerizing a polyamide resin prepared by melt-polymerizing a diamine component containing 70 mol % or more of metaxylylenediamine and a dicarboxylic acid component containing 70 mol % or more of adipic acid, and preferably has a relative viscosity of 2.3 to 4.2 when measured at 25.degree. C. using a solution of 1 g polyamide resin in 100 ml of 96% sulfuric acid. By adding at least one compound selected from the group consisting of the specific metal salt of fatty acid, the diamide compound and the diester compound to a solid phase-polymerized polyamide resin, shaped articles such as films, sheets and hollow containers made of the solid phase-polymerized polyamide are improved in the resistance to whitening during storage tinder a high humid condition, upon contacting with water or boiling water, or upon heating to a glass transition temperature or higher.