Corrosion products on 23 bronze dagger-axes unearthed from different tombs dating to the Warring States period at Yujiaba site, Kai County, Chongqing, China, were characterized non-destructively by Raman spectroscopy and optical microscopy (OM). The results showed that Cu corrosion products such as Cu hydroxide sulfate, Cu hydroxide carbonate, Cu hydroxide phosphate, Cu chloride hydroxide, Cu sulfide, Cu oxide, Pb corrosion products such as Pb oxide, Pb carbonate and Pb chlorine phosphate/arsenate (Pb5((As,P)O4)3Cl), and Sn oxide were all detected. Of 23 bronze dagger-axes, 15 were found with mimetite-pyromorphite, whereas 2 with Cu chloride hydroxide may indicate that chlorine ion can combine with Pb more easily than Cu in this special environment. Sulfate ion, phosphoric ion, chloride ion, carbonate ion or bicarbonate ion, and microorganism in the buried environment are the main factors which influenced the formation of corrosion products. Because these bronze dagger-axes were all unearthed in the tombs, the phosphoric ion in the buried environment should come from hydroxyapatite (Ca5(PO4)3OH) which is the main inorganic phase of human bones and teeth in the tombs.