The seasonal variations of δ 18 O values and concentrations of major ions (Ca 2+ , Mg 2+ , NH 4 +, SO 4 2- , NO 3 -, Na +, Cl - and K +) recorded in the 14 m firn core, which was recovered from the Dasuopu Glacier, are analyzed to understand the characteristics of seasonal variations of atmospheric environment in the Mt.Xixiabangma. The analyses of the correlation and EOF show that δ 18 O values are evident positive correlation with Ca 2+ , Mg 2+ , NH 4 +, SO 4 2- ...