A thermoplastic resin composition includes a thermoplastic resin (A) and a reactive functional group-containing resin (B), which has a specific structure in the morphology of the resin composition observed by transmission electron microscopy tomography, and the relaxation time T1C of each carbon nucleus by the solid NMR measurement of the thermoplastic resin composition containing a polyamide resin is kept in a specific range. The composition is excellent in the balance between contradictory properties such as impact resistance and heat resistance, remarkably exhibits a peculiar viscoelastic behavior not observed in the conventional polymeric materials, and is remarkably excellent in impact energy absorbing performance and vibration energy absorbing performance at the time of high-speed deformation.