Abstract <p>Atomic-scale molecular dynamics simulations were utilized to track the correlation between microstructural evolution and macroscopic properties of Mg–Al metallic glass formed at different cooling rates in this work. The results show that the level of order in atomic arrangement in Mg–Al metallic glass decreases with the increase of cooling rates. Voronoi analysis indicate that the content of icosahedral-like clusters was always the highest in Mg–Al metallic glass cooled at different rates, followed by mixed clusters, and crystal-like clusters was the lowest. It is also found that the tendency of Al atoms to form perfect icosahedron is higher than that of Mg atoms. Uniaxial tensile simulations show that the elastic modulus of Mg–Al metallic glass decrease as the cooling rate increases, which is consistent with the change trend of icosahedral-like clusters content with the cooling rates. This study provides theoretical guidance for understanding the cooling-rate effects in metallic glasses and may inform the development of new metallic glasses via rapid solidification.</p>