In this paper, we have studied the ageing effect before and after quenching at two temperature of 400 and 500 °C of Al 6000 alloy. The Al 6000 alloy was aged at 300 °C for 48 hours. The structural properties were investigated using X-ray diffraction; themicrostructural evolutionwas investigated using optical, scanning and transmission electron microscopies and microhardness measurement for the mechanical properties. After various states of ageing, the Al-Mg-Si alloy shows significant changes in the microstructure and mechanical behavior. After ageing, the microstructure of the matrix consisted of a two solid solution of áÂAl and âÂMg2Si phases precipitation.After two-step ageing at 300 °C and quenching, corresponding to theminimumvalue ofmicrohardness, the alloy reveals small â continuous precipitates.After ageing at 300 °C of original sample, the volume fraction of this precipitate becomes higher. We found be that the best results have been obtained with the quenching at 500 °C.