Groundwater is the most important source of fresh water supply for drinking all over the world. Groundwater samples from different location of Jhenaidaha Municipality have been analyzed to assess the chemical composition, source rock and quality. The parameter analyzed for the research are pH, TDS, EC, Na+, K+, Ca2+, Mg2+, Cl-, HCO3-, SO42-, PO43-, H4SiO4 and NO2-N. The analysis reveals that the cations and anions of the water shows the order of dominance as Ca2+>Mg2+> Na+>K+ and HCO3->Cl->SO42- respectively. The Na+/ (Na++Ca2+) weight ratio against TDS illustrates that the water is derived...