The Northern Qilian high-pressure metamorphic belt has experienced multiple deformation-metamorphism, which consists of at least four stages.In 550.8-526 Ma, eclogites were formed. High temperature and pressure caused the escape of a large quantity of gas-liquid fluids from rocks while silicate melt was generated. In the late stage, small amounts of CO2 and H2O infiltrating along fractures were introduced.In the formation of glaucophane schist (447-362 Ma), devolatilization reactions were dominated during the subduction-uplift stage of the paleoplate.In the uplift-exhumation stage (400-380 Ma) the increase of internal space of fractures in the rocks favoured fluid infiltration and concentration. These fluids participated in hydration reactions in the retro-metamorphism. The fluids participating in the mineral reactions have the compositions of CaCl2-NaCl-H2O.In subsequent thrusting (<380 Ma), the metamorphic terrain was uplifted to the shallower crust and ductile-shearing deformation took place, which c The Northern Qilian high-pressure metamorphic belt has experienced multiple deformation-metamorphism, which consists of at least four stages. 550.8-526 Ma, eclogites were formed. High temperature and pressure caused the escape of a large quantity of gas-liquid fluids from In the late stage, small amounts of CO2 and H2O infiltrating along fractures were introduced. In the formation of glaucophane schist (447-362 Ma), devolatilization reactions were dominated during the subduction-uplift stage of the paleoplate The in the uplift-exhumation stage (400-380 Ma) the increase of internal space of fractures in the rocks favored fluid infiltration and concentration. These fluids participate in hydration reactions in the retro-metamorphism. The fluids participate in the mineral reactions have the the compositions of CaCl2-NaCl-H2O. Following thrusting (<380 Ma), the metamorphic terrain was uplifted to the shallower crust and ductile-shearing deformation t ook place, which c