The characterizations on the microstructural and mechanical properties of the Mg-Al-Zn multi-element intermetallic alloys fabricated by friction stir processing (FSP) are presented. The composites of the alloys vary within Mg35-70Al5-25Zn25-45. The maximum working temperature can reach 550oC. The current process applies the FSP on vertically stacked foils of various portions of Mg, Al and Zn, 99.9% in purity and 0.2 to 1 mm in thickness. In order to homogenize the alloy composition, three or more FSP passes in opposite directions are applied. Depending on the relative contents of Mg, Al and Zn, numerous intermetallic compound phases are induced. The resulting intermetallic alloys exhibit high hardness up to 350 Hv.