The through-thickness variations of strain and microstructure during high-speed hot rolled 5052 aluminum alloy sheet were investigated. The specimens were rolled at temperature ranges from 410 to $560^{circ}C$ at a rolling speed of 15 m/s without lubrication and quenched into water at an interval of 30 ms after rolling. The redundant shear strain induced by high friction between rolls and the aluminum sheet was increased largely beneath the surface at a rolling reduction above 50%. Dynamic recrystallization occurred in the surface regions of the specimen rolled under conditions of high temperatures or high rolling reductions.