Ozone has strong oxidation and corrosion effect on cultural relics, especially on silver relics, in the museum environment. In this study the quartz crystal microbalance (QCM) was used for investigation of mass change of' silver - electrodeposited quartz crystals at different ozone concentrations and at different relative humidies. The mechanism of silver corrosion by ozone was also investigated. The results showed that the concentration of ozone has a great influence on silver corrosion. With an increase in ozone concentration, the mass of the silver surface gradually increased and the extent of corrosion became aggravated. Silver is less sensitive to relative humidity. At different relative humidities, the mass change of the silver surface was similar. When exposed to ozone, silver initially reacts with atomic oxygen formed from ozone decomposition to form silver oxide (Ag2O). As Ag2O film grows thicker, a layer of silver peroxide (AgO) forms on the top of the oxide film. AgO is formed by reaction between Ag2O and atomic oxygen.