Provided is a thermoplastic resin composition which exhibits little dependence of air permeability on fatigue. The present invention is a thermoplastic resin composition which comprises an ethylene-vinyl alcohol copolymer and a polyamide resin, said thermoplastic resin composition being characterized in that only one maximal peak point assignable to crystallization is observed in the curve of heat flow versus temperature as determined by differential scanning calorimetry of a melt-kneaded mixture of 25 parts by mass of the ethylene-vinyl alcohol copolymer and 75 parts by mass of the polyamide resin in a cooling process.

Disclosed is a semiaromatic polyamide resin composition including a semiaromatic polyamide (A) and a polyhydric alcohol (B), wherein a mass ratio (A/B) between the semiaromatic polyamide (A) and the polyhydric alcohol (B) is 99.95/0.05 to 90/10; and the semiaromatic polyamide (A) includes as constituent components thereof an aromatic dicarboxylic acid component and an aliphatic diamine component, and has a melting point of 300 to 350 C.

Disclosed is a semiaromatic polyamide resin composition including a semiaromatic polyamide (A) and a polyhydric alcohol (B), wherein a mass ratio (A/B) between the semiaromatic polyamide (A) and the polyhydric alcohol (B) is 99.95/0.05 to 90/10; and the semiaromatic polyamide (A) includes as constituent components thereof an aromatic dicarboxylic acid component and an aliphatic diamine component, and has a melting point of 300 to 350 C.