The present study was to assess the quality of ground water from various parts of Thanjavur district, and check its fitness for drinking purpose. The pH was determined by pH metric method, calcium, magnesium, chloride were analyzed by titration method, sulphade, iron, nitrate, nitrite, chromium were estimated by spectrometric method ,total dissolved solids of the water samples were determined by gravimetrically, colour of the water samples were determined by platinum-cobalt method ,taste of the water samples were determined by taste rating method, turbidity of the water samples were determined by Nephelometric method etc., are determined for some parts of Thanjavur district water samples and compared with standard limits recommended by BIS. Comparative study of groundwater for this region can be used for the quality of water is suitable for drinking purpose, but the ground water sample numbers S2, S3, S4, S5, S6, S7 and S9 is not suitable for drinking purpose, because in the presence of excess of hardness (Ca2+, Mg2+), chloride, and TDS.