Abstract: The flow behavior and dynamic recovery and recrystallization，as well as microstructure evolution，of AA7005 aluminium alloy in hot compression were investigated. A hyperbolic sine relationship can satisfactorily correlate temperature and strain rate with flow stress through an Arrhenius term that involves thermal activation parameters during steady state deformation of the alloy. The hot deformation for the alloy is a thermally activated process，which is governed by rate-controlling mechanisms of dislocations. The main dynamic recovery mechanisms of the alloy are proposed to be cross-slip of jogged screw dislocations and climb of edge dislocations. Typical subgrain structures are highly developed when the alloy is softened by dynamic recovery. The mean size of the subgrains increases with decrease of the natural logarithm of Zener-Hollomon parameter. Local geometricdynamic recrystallization is activated when the alloy is compressed at higher temperatures and lower strain rates，while the flow curves decrease gradually with increase of true strain. Fine eqiaxial recrystallized grains with large-angle grain boundaries，which are different from the original elongated grains，developed resultantly.

Key words: compression； flow stress； subgrain； geometric dynamic recrystallization