The spatial and temporal variations of groundwater chemical types and their genesis were discussed by measuring ion concentration and hydrogen and oxygen isotopic compositions in the Anshan-Haicheng area,Liaoning Province. The measurements showed that the water temperatures ranged from 11.0℃ to 97.0℃,and the total dissolved solids(TDS)of the water samples ranged from 197.89mg/L to 829.99mg/L. The water samples can be divided into 8 chemical types. The δD and δ¹⁸O values of the most water samples are distributed along the atmospheric precipitation line in the eastern monsoon region of China. A few deviations indicated that the well water in the study area was mainly recharged by atmospheric precipitation,but the hot spring water mixed with small amount of deep fluids. The Ca-HCO₃ and Ca·Mg-HCO₃ waters resulted mainly from rock weathering dissolution and cation exchange;Ca-HCO₃·Cl and Ca·Na-Cl·SO₄,waters from rock weathering dissolution with deep brine mixing or likely sewage pollution;Ca-HCO₃·SO₄ and Ca-SO₄·HCO₃ waters from rock weathering dissolution and deep fluid mixing;Na-SO₄·HCO₃ and Na-HCO₃·SO₄ waters from atmospheric precipitation with the mixing of deep source fluids. The obvious chemical anomalies of the ground waters were well correspond to two earthquakes of M_L ≥ 3.0 in the study area during the sampling duration. The Na⁺,Mg²⁺,Ca²⁺,Cl^-,and SO₄^2- can be considered as the sensitive indicators to local seismic activity.