The Chundu complex porphyry body consists of diorite porphyrite stock and granodiorite porphyry dike. The latter is the minerogenic mother rock of porphyry copper deposits. According to the geochemical feature, such LIL elements including Cs, Rb, K, Ba and Sr are apparently concentrated, while opposite for those inactive HFS elements including Y, Hf, Zr, Ti, Nb and Ta. It indicates that magma originated from upper mantle or lower crust with crust substance involved in. With the help of tectonic background, porphyry rocks formed in volcanic arc structural environment of active continental margin, which can be regarded as the outcome of westward subduction of oceanic crust along Ganzi-Litang trench.