Ground water samples collected from different localities in and around Paravanar River sub basin, Cuddalore District, Tamil Nadu were analyzed for their physico- chemical characteristics. This analysis result was compared with the WHO standards of drinking water quality parameters with the following water quality parameters namely pH, Electrical conductivity, calcium, magnesium, alkalies, chloride, bicarbonate and sulfate equivalents, total dissolved solids and total hardness, etc., The usefulness of these parameters in predicting ground water quality characteristics were discussed. Hydrogeochemical facies of groundwater of study area reveals fresh to brackish and alkaline in nature.Piper plot shows that most of the groundwater samples fall in the mixed field of Ca-Mg-Cl type. From the plot, alkaline earths (Ca and Mg) significantly exceed the alkalis (Na and K) and strong acids (Cl) and (SO4) exceed the weak acids (HCO3) and (CO3). The physical and chemical parameters of the Paravanar River Basins results shows that all the samples are under recommended limit for industrial purposes.