In order to find out the preservative state and patina structure of the bronzes unearthed at Yangfutou tombs in Kunming and their alloy composition, metallurgical technology and manufacture technics, 32 samples were collected from different objects and fragments. Then the SEM-EDX and XRD methods were taken to measure alloy composition and corrosive products. It revealed that those bronzes were made of many kinds of metals and the main alloy type of bronzes were Cu-Sn alloy, others were red copper, Cu-Sn-Pb and Cu-Pb-Sb alloys. The corrosive products were mainly consisted of malachite, cassiterite, quartz and cuprite.