A're porphyry is located at the north end of the Zhongdian Arc, which is consistent with the direction of the Geza Fault (NNE). It is mainly composed of amphibole diorite porphyry, clinopyroxene diorite porphyry, clinopyroxene amphibole diorite porphyry and qaurtz diorite porphyry. Accroding on the distribution of the phenocrysts in A're porphyry, we study the petrography and mineral chemistry of the amphibole diorite porphyry, clinopyroxene diorite porphyry, clinopyroxene amphibole diorite porphyry and the schlieren. The result display that both of the amphibole and clinopyroxene can be divided into high Mg# and low Mg#, furture with the disequilibrium textures which formed by magma mixing, and crystallization fraction is not obvious; these magmas are connected to the subducting Ganzi-Litang ocean slab of Late Triassic and related to the partial melting of the overly mantle which experienced the fluid and melts from Ganzi-Litang slab, and the magma process are controlled by tectonic stress. These magmas were poor in water or local water-rich, and then they became water-rich, meanwhile the geochemical characteristics changed, such as from high MgO and SiO2/Al2O3 ratio to the low MgO and SiO2/Al2O3. The amphibole geothermobarometry exhibits the pressure of low mg #amphiboles, which formed at early stage, are higher than the high Mg# amphibole. Based on the magma tectonic setting, tectonic stress and dynamic background, we believe that with the westward subduction of the Ganzi-Litang Ocean slab and eastward extrusion of the Qiangtang Block (~230Ma), and the ocean slab may break-off during 228~219Ma, the tectonic stress in the research area increased firstly and subsequently reduced.