Aluminum (Al) is widely used in industry because it is lightweight and strong. Magnesium (Mg), which is also lightweight and strong, is often alloyed with Al to form AlMg alloys that have high mechanical strength for various engineering applications. Simulations were performed at room temperature (300 K) with varying Mg concentrations of 0%, 5%, 10%, 15%, and 20%. The simulations were performed using the LAMMPS software with the EAM (Embedded Atom Method) potential approach. The primary focus of this study was to investigate the alloy's response to tensile and compressive loads at the atomic level, as well as changes in its crystal structure. The tensile test simulation results showed the highest maximum stress value in pure Al at 8.02 GPa, elastic modulus of 50.62 GPa, and yield point of 1.29 GPa. In compression testing, the highest maximum stress value of 5.77 GPa was observed in pure Al, with a yield stress of 5.33 GPa and an elastic modulus of 77.02 GPa. From an atomic structure perspective, the addition of Mg causes changes in the crystal structure, particularly a decrease in the number of FCC (Face-Centered Cubic) structures and an increase in other structures such as HCP, BCC, and amorphous. This structural transformation affects the mechanical properties of the AlMg alloy.