The through-thickness variations of strain and microstructure of high-speed hot rolled 1050 pure aluminum sheet were investigated. The specimens of 1050 aluminum were rolled at temperatures ranging from 410 to 560oC at a rolling speed of 15 m/s without lubrication and quenched in water at an interval of 30ms 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%. Recrystallization occurred in the surface regions of the specimen rolled to reduction of 65% at 510oC, while only recovery occurred in the other regions.