Define the Yingba metamorphic core complex systematically. Three types of deformation are recognized in the evolution of Yingba MCC. Temperatures estimates demonstrate an intermediate to high temperature (400–650 °C) shear zone. Vorticity calculation indicates a pure shear-dominated (48–62%) general shear in the middle crust. Yingba MCC is caused by the extension after previous thickening, and is a part of the large extensional region in NE Asia.