The Archean metamorphic rocks in Miyun area consist mainly of supracrustal rocks and gneisses of tonalite-trondhjemite-granodiorite (TTG) composition.In the supracrustal rocks, there are many characteristic fabrics, such as symplectic coronas of Opx and retrograde metamorphic rim of Di and/or Gt.According to correlations between mineral inclusions and metamorphic reactions,the metamorphic minerals are composed at least of four generations, which represent four stages of the granulite facies metamorphism in this area. According to above-discussed metamorphic mineral assemblages and mineral reaction as well as metamorphic P-T estimates, metamorphism of the supracrustal rocks in Miyun area is characterized by an anticlockwise type PTt path .