Peraluminous sapphirine and Al rich spinel were discovered in rodingitized amphibolite in the Dongdegou，Zhaosu County，southwestern Tianshan Mountains，the content of Al2O3 in sapphirine is between 6482% and 6636%，in Al rich spinel between 6524% and 6854%. According to the sapphirine bearing mineral assemblages and mineral reaction textures，using the Theriak—Domino software，the metamorphic process of the bulk rock was simulated. The results showed that the peak temperature—pressure conditions were 700~780 ℃，065~075 GPa，reaching granulite facies metamorphic conditions. The peak metamorphic reaction is：amphibole (Am) + spinel (Spl) + anorthite (An) = chlorite (Chl) + diopside (Di) + sapphirine (Spr). Rocks experienced an Al rich fluid/melt metasomatic metamorphism of high temperature. The occurrence of sapphirine bearing granulite facies rocks adds new insight for the complicated metamorphic processes of rocks in supra subduction zone of the southwestern Tianshan Mountains, showing important geological implications.