Average roughness is an increasingly important method in material sciences. The searching for a possible correlation between average roughness and impact energy are current interest. This paper present the results of an experimentally study made on the correlation between the average roughness and the impact energy in aluminum alloy by using scatted diagram. The impact energy of aluminum alloy was obtained by using Charpy Impact Test. The micrographs of fractured aluminum alloy were analyzed with the IFM (Infinite Focus Measurement) profile to determine the parameter of average roughness. The result shows the relationship maybe established between average roughness and impact energy.