This presentation shared some information regarding how stable isotope studies can help Hydro-Meteorologist to fill the gaps in the database, which is valuable for better river basin management. The presentation had not limited to a specific case study and included brief background and some examples of several case studies. It covered the following outlines: • Introduction (with focus on how hydro-meteorological data are important for better river basin management) • Some challenges in hydro-meteorological data collections • Introduction about stable isotope • Stable isotope application in hydrometeorology • Example of how stable isotope can fill the gaps in hydro-meteorological databases • Summary and conclusion