Diancang Shan complex, lying to the northwest extension of the Ailao Shan-Red River shear zone, experienced very intense left-lateral stricke-slip shearing and metamorphism. High-temperature mineral assemblages are preserved in sheared rocks and show typical high-temperature macro- and microstructure characteristics. A remarkable feature of the mylonites is their extremely strong stretching lineation fabrics forming L and L>>S tectonites. Such fabrics occur in both sheared metamorphic rocks and sheared granitic plutons. Microstructures, mineral deformation features and textures of deformed minerals from high-temperature mylonites collected from Diancangshan are studied. U-Pb zircons from a granitic high temperature mylonite are dated by SHRIMP. The results reveal features of intensive ductile deformation and oriented growth of feldspar, quartz and amphibole, in responding to shearing and metamorphism at amphibolite facies. Microstructural features also consistent with left-lateral shearing. Structural and microstructural studies of the mylonitized porphyritic monozogranite reveal a progressive evolution from emplacement of magma, subsolidus flow, late magmatic replacement to solid state shearing. It is suggested that the upwelling and emplacement of the magma are controlled by left lateral shearing and progressive shearing strongly affected the emplaced magmatic rocks. On the other hand, macrostructural analysis reveals that the high temperature granitic mylonites are mainly confined to the shear zone, has experienced shear deformation and extends along the shear zone. All above evidences suggest synkinematic feature of the magmatic intrusion. Meanwhile, thermochronological dating of zircons from the granitic mylonite give U-Pb ages of 30.88±0.32 Ma, which provides an upper limit timing of Diancangshan left-lateral shearing. We would strongly argue that the left lateral shearing along the Ailao Shan-Red River shear zone in Diancangshan area initiated no later than 30.88±0.32 Ma in early Oligocene.