Abstract: The flow behaviors of 6005A and 6082 aluminum alloys were investigated by high-temperature isothermal compression on a Glebble-1500 thermal-mechanical simulator at deformation temperatures of 450 to 550℃ and strain rates of 0.005 to 10 s^-1. The flow stress curve of 6005A aluminum alloy exhibits a waveform character at different deformation temperatures under the condition of low strain rate. With increasing strain rate the competition between softening and hardening closely reaches to a balance so that the flow stress appears as a steady state. At high strain rate, the hardening is dominant during the hot deformation and there is a waveform increase in the flow stress curve because of the competition between reverting and hardening. The flow stress curve of 6082 aluminum alloy, however, does not show the waveform character at low strain rate. A steady-state stress is also displayed at medium strain rate. But the waveform flow curve is shown at high strain rate. Both of the alloys are positive strain rate sensitive materials and their hot deformation is controlled by the thermal activation. Finally the relationships among flow stress, strain rate and deformation temperature were proposed for 6005A and 6082 aluminum alloys, respectively.