Abstract: Solution treatment and aging treatment of the new extruded aluminum alloy Al-Mg-Si were investigated by mechanical properties tests, SEM, DSC and metallographic microscope to supply the references for the heat treatment plans of productions and further experimental research. The results showed the over-burnt temperature of the extrusion is 572°C and the melting temperature is 594°C. Solution treatment at 560°C for 2 hours and aging treatment at 170°C for 12 hours are the optimal peak-aging treatment condition. The corresponding mechanical properties are 406 MPa in UTS, 340 MPa in yield strength and 18.37% in elongation. The fully recrystallization are observed in the extrusion, resulting in disappearing of the work hardening phenomenon.