Abstract: The Yanbei porphyry tin deposit (Sn-F type) is characterized by enrichment of topaz of magmatic origin and thus differs from the world-famous Bolivian porphyry tin deposits (Sn-B type)which were rich in tourmaline. The ore hearing parent rocks are Mesozoic volcanic intrusive complex. They have high silica, peralumina, enriched incompatible elements weak Ce and intensive Eu negative anomalies and lower εNd values, high 205Pb／204Pb and higher (87Sr／86Sr), and δ18O values. These features indicate that the ore-bearing parent rocks were derived from the crustal materials and belong to the continental crust remelting type. The ore bodies were located at the contact zone of granite porphyry with rhyolite porphyry in great thickness and homogeneous mineralization. Mineralogical composition of the deposit is relatively complex, of which cassiterite. pyrite and chalcopyrite are dominant, sphalerite and galena are less important. The wall-rock alterations are intense in mining district and are roughly grouped into three zones in space: topazitization, chloritization and sertctltzatton from granite porphyry to fresh country rocks. The potassic zone which is typical for other porphyry type deposits is very weak in this ore district. The ore forming temperatures are mainly in the ranges of. 339-324℃, 280-228℃ and 180-129℃ .displaying polymodaI distribution feature. The ore forming solution has 6 0 value of 7. 8-4. 2‰ and δ18O value of-49‰ to -6l ‰ indicating that it consisted dominantly of magmatic water. Lead isotopic compositions of pyrite are similar to those of feldspar in volcanic intrusive complex and δ44S values (-0. 3‰-1. 5‰) of pyrite close to zero. These characteristics suggest that the ore forming materials were mainly derived from the magma. Therefore, the mineralization of Yanbei porphyry tin deposit is closely related to Mesozoic volcanic-intrusive complex in time, space and material; source.