The Paleoproterozoic Badu Group in southwestern Zhejiang Province is the oldest metamorphic basement in the Cathaysia block, and its metamorphic grade was previously considered to be only of amphibolite facies. The garnet from the pelitic granulite developed both diffusion zoning and symplectite of plagioclase related to the lowering of temperature and pressure, respectively. A clock-wise pT path has been constructed for the pelitic granulite which is consistent with the thinning process of the thickened continental crust.