Recently, bi-metals have been widely used in many industries such as aerospace, motor vehicles and electronics. This issue has stimulated researchers to study the properties of such composites and their fabrication methods such as extrusion, rolling and casting with sacrificed foam. Bi-metals have been built to meet special specifications that could not be fulfilled by a single metal only. Bimetals are jointed together through mechanical and/or metallurgical bond. Al-Mg is one of the most widely used bi-metals that have low-weight and high-strength simultaneously. Although the formability of magnesium is low, high-formability of aluminum improves the formability of Al-Mg bimetal. In this study, because the temperature and strain between the layers cannot be experimentally measured during of the extrusion process, the hot extrusion process for 5 layers of Al-Mg bimetal consisting 3 layers of aluminum and 2 layers of magnesium was simulated using Abaqus finite element package. The simulation results were then used to study the process parameters including friction coefficient, strain, von Mises stress and temperature. The results showed that the friction coefficient for this process was different in 350 °C and 400 °C. The friction coefficient was also experimentally obtained using ring compression test. Furthermore, it was found that the optimum mechanical properties of the composite such as ductility and yield strength were obtained in 400°C. Furthermore, the ring compression test results showed that bonding was formed between layers in 350 °C and 400 °C. Key words: Aluminum, Magnesium, bi-metal, Hot extrusion