Geza arc is an important part of Yidun island arc in the southwest Sanjiang tectonic magmatic belts. The lead isotopic compositions of ore mineral, with ²⁰⁶Pb/²⁰⁴Pb ranging from 17.680 to 19.165, ²⁰⁷Pb/²⁰⁴Pb ranging from 15.453 to 15.773, ²⁰⁸Pb/²⁰⁴Pb ranging from 37.730 to 39.654, was relatively stable and chartered by depleted uranium, rich thorium. There was a significant positive correlation between lead isotopic composition and characteristic parameters (Δβ and Δγ, V₁ and V₂). Based on the lead structural pattern recognition and the original classification of comprehensive analysis, the lead isotope of Geza island arc metallogenic belt is mainly derived from the mantle and the lower crust, with the crust-mantle mixed source characteristics. The mineralization is closely related with magmatic activities.