It was manufactured by adopting aluminum alloy as the candidate alloy of lightweight alloy to be used for interior and exterior materials of high-speed train. The cast product was extruded using the AS (air slip casting) casting method and the DC (direct casting) casting method and this was again heat-treated with T5 or T6. The remarkable point is that the extrusion temperature and pressure of 6xxx alloy were somewhat higher than those of other alloys. The reason is that 6061 alloy exhibited brittle fracture due to grain boundary segregation even at the tensile fracture surface, and the fact that the product used a billet by DC casting method. The characteristics of the casting material showed the mechanical characteristics that are not inferior to those of the foreign materials. The hardness, microstructure and tensile properties of the 6063, 6N01, 6061, 6060, 6005 and 5083 aluminum alloys selected as present study by literature research were similar to those of external materials (made by Alcan, Canada).