The geological sample were digested by HCI and HNOa in this experiment. The (NH4)2SO4 solution was used as modification. The graphite furnace atomic absorption spec- trometry with zeeman background correction was applied to determinate trace Ag in the sam- ples. The results showed this method was convenient and pricise. The RSD ranged from 1.89% to 6.70% and recovery rate was between 94%-106%.