Stable isotope analysis of water means the determination of oxygen and hydrogen isotope ratio ofwater. Stable isotope studies play an important role in the hydrological, climatological, palaeoclimatological researches and recently the fields of application of deuterium depleted water caught the attention of cancer researches.Heavy water is used as a neutron moderator and coolant for nuclear reactors. Deuterium is also a potential fuel for commercial nuclear fusion. The deuterium (2 H, D) or a heavy hydrogen is the stable isotope ofhydrogen with the natural occurrence one atom in 6420 of hydrogen (i.e. 150 ppm), for stable isotope measurements a few millilitres of water is required.