Noticing a boom of experimental data and studies from relativistic heavy-ion collisions at RHIC and LHC these years, I will discuss some recent hot topics related to high-energy nuclear physics, mainly including initial fluctuations and higher-order anisotropic flows, shear viscosity of quark-gluon plasma, and beam-energy scan program. Results from a multiphase transport model are shown to explain the experimental data reasonably well.