Abstract: Aluminum alloys are anodized for enhanced resistance to corrosion and for the improvement of dyeing, lubrication and adhesion processes. In this research, an anodization process was carried out on AA 5356 by studying two different parameters (time and concentration of sulfuric acid). Hardness test and impact energy test were adopted to check the effect of anodizing on the alloy. The anodic layer thickness of all the specimens was measured and from the results, it was found that the thickness increased with an increasing time and sulfuric acid concentration. An increase in the time of anodizing more than 15 min and a sulfuric acid concentration of more than 5% increased the toughness of the material by about 40% and decreased the hardness by about 14%. The thickness of the anodic layer increased with an increasing electrolyte concentration more than increasing the anodizing time and this led to more decrease in the hardness.