This study sought to explore the physical-chemical Characteristics of groundwater quality in Olakkur block, which is located in Villupuram district, is water starved region for the past few years due to insufficient rainfall, led to the groundwater depletion and affect the groundwater quality. Ground water samples were collected from different localities in and around Olakkur block. Analysis result was compared with the WHO standards of drinking water quality parameters namely EC,TDS, Calcium, Magnesium, Sodium, Potassium, Nitrate, carbonate, bicarbonate, Fluoride etc. The usefulness of these parameters in predicting ground water quality characteristics is discussed. The quality of ground water in the study area is classified into fresh to brackish water and moderately hard to very hard water. From the overall evaluation of collected groundwater sample it is observed that the water from the study area is suitable for drinking purposes. Groundwater Chloro-Alkaline-Indicies (CAI) suggests that there is an exchange of water Mg2+ and Ca2+ with rock Na+ and K+ . The calculated values in RSC, SAR, Na %, show that the water is suitable for Irrigation purposes.