Abstract: The meteoric origin of geothermal water in study area is evidenced by its environmental isotope composition.The geothermal water can be classified into three categories based on the time when replenishment take place and mixing extent with normal groundwater which are:geothermal water mixing with normal groundwater recharged mainly by the modern meteoric water;geothermal water mixing with normal groundwater water recharged by both ancient and modern meteoric water;deep-runoff geothermal water recharged mainly by ancient meteoric water.