Groundwater is a important natural resource that is essential for human drinking and irrigation purposes.The fast industrial growth and unsuitable agricultural practices have affect the water sources. The present work evaluates the different ground water quality parameters at various locations of Ariyalur block, Tamil Nadu. Ground Water samples were analyzed for various water quality parameters like pH, Turbidity, Electrical conductivity(EC), Total dissolved solids(TDS), Total hardness(TH), Calcium(Ca2+), Magnesium(Mg2+), Sodium(Na+), Potassium(K+), Iron(Fe), Nitrate(NO3 -), Chloride(Cl-), Fluoride(F), Sulphate(SO4 2-) and Total Alkalinity(TA) to evaluate their quality. All the parameters compared with Indian and WHO standards. The analysis results indicate that the water have high values of Hardness, Alkalinity and Total dissolved solids in the most of the samples, which makes the water unsuitable for drinking purposes.