PURPOSE: To obtain a thermoplastic resin composition useful for mechanical parts, etc., as a resin-based sliding material, having excellent wear resistance, heat resistance and moldability by blending a thermoplastic polyamide-imide resin having a specific structure with graphite in a prescribed ratio.

CONSTITUTION: The resin composition comprises (A) 90-70wt.% of a thermoplastic polyamide-imide resin, a random copolymer of the formula [(l), (m) and (n) are molar ratios respectively, (l):(m+n) is 5:95-30:70 and (m):(n) is 5:5-9:1] having 10,000-300,000 molecular weight and (B) 10-30wt.% of graphite.