Abstract: Along the Lancang River in Jinggu County, Yunnan Province, a series of Lower Paleozoic schists which are dominant by sericite and quartz tectonic schists distribute in NNW-SSE direction. The schists have undergone intensive rheology, and abundant lentoid and veinlet quartz veins are well developed. It′s indicated from both the macro and micro tectonic deformation structure that the quartz veins are syn-tectonic recrystallized, and the forming mechanism is closely related to mineral dissolution, transfer and recrystallization in ductile shear belts. On the basis of data from quartz inclusion experiments, these quartz veins were formed under the metamorphic condition of 500℃ and 0.498GPa, which is consistent with middle to high greenschist facies.