To study the change of corrosion of excavated bronzes in new conservation environment, 27 pieces of Western Zhou Dynasty bronzes of a vault in Meixian, Baoji after one year and half excavation were taken as samples. The corrosion types and characteristics were analyzed and described. The results showed that the main type of corrosion of the bronzes was the atmospheric corrosion in closed environment; the corrosive products were mainly carbonates and oxides, but harmful chlorides were also detected on one of the bronzes. The change of the conservation environment before and after excavation was the main factor of corrosion.