Ancient mining and smelter remains in Nanling counly, Anhui province show that this region is one of earliest and biggest metallurgical industry centers in the lower reaches of Yangzi river of China. The earliest Jiangmuchong site was dated to the late West Zhou dynasty. Microstructures and compositions of various bronze samples from Nanling county and dated from late West Zhou Dynasty to Spring and Autumn and Warring Stales periods were investigated. Examination reveals that some vessels are copper-lead or copper-tin-lead alloys. However, those made by hot forging, followed by quenching do not contain lead, but rather have a tin content that is right for the technique and good for their properties. Weapons, tools and horse and cart decorations are all copper-tin alloys, suggesting that the bronze artisans at the time had a good understanding of the relationship between an alloy's composition and its properties. The body of a Ding in the Yue style shows a martensite structure formed by hot forging followed by quenching. Similar structures were found in bronze gongs and cymbals dated to the Han Dynasty (206 B. C. - A. D. 220), bronze sword from the Xia-jiang region dated to the mid - to - late Warring States period, and bronze vessels excavated from pit storage and dated to the Southern Dynasties. Two bronze weapons (Ge) , from the Wu state, have structures that show quenching after casting, a slightly different technique. The working of these bronze structures is not accidental; in fact these bronzes show that the hot working and quenching technique was applied to high tin bronze dating back to at least the Spring and Autumn and Warring states periods and that the technique was used to improve mechanical properties of high tin bronze alloys.