The discovery of the Xiongcun ore district is an important ore-prospecting breakthrough for Jurassic mineralization in the southern Gangdise metallogenic belt, Tibet. The No. Ⅰ, No. Ⅱ and No. Ⅲ copper-gold deposits were discovered in the Xiongcun ore district. In order to find out the relationship between porphyry mineralogical characteristics and the mineralization,the authors chose the ore-bearing porphyry of No. Ⅰ deposit as the research object. According to the modes of occurrence and electron microprobe data, biotite, muscovite, andalusite and rutile are products of hydrothermal alteration, whereas the orthoclase is mostly of hydrothermal origin with less magmatic origin. Such characteristics as abundant hypogene pyrrhotite, no anhydrite crystal, predominant ilmenite over magnetite, apatite with low SO₃ content (≤0.03%) and a large amount of methane in the ore-forming fluid indicate that the oxygen fugacity of the magmatic-fluid is low and the No. Ⅰ deposit of Xiongcun may be a reductive porphyry copper deposit. Temperatures measured by Zr-in-rutile thermometer are 622～762℃, which reflect the crystallization temperature of rutile and the middle-late stage temperature of potassic alteration. The larger grain sizes and relative enrichment of V₂O₅ (averaging 0.42%) in rutile and higher Mg, K and F with lower Ca in biotite are indicative of high-grade copper mineralization.