Abstract: Tensile test at room temperature and Kahn tear test were conducted to investigate the evolution of the microstructure and mechanical properties of Al-5Zn-3Mg-1Cu thick plate during the hot rolling by means of OM and TEM． The results show that (1) during the hot rolling of the aluminum alloy，both the deformation and the fraction of recrystallization increase respectively from 56% and 0. 49% to 91% and 43. 30%，while the grain size decreases from 83μm to below 10μm; (2) meanwhile，the tensile strength and yield strength of the aluminum alloy increase respectively from 542. 3 and 520. 0MPa to 593. 4 and 564. 9MPa，and the elongation increases from about 8. 0% to 11. 2%; and (3) as the deformation increases，the tear strength (TS) and UIE of the aluminum alloy tend to increase．

Key words: aluminum alloy, rolling deformation, mechanical properties, tensile test, Kahn tear test