The study of the interrelationship between groundwater and surface water is crucial in groundwater basin research. As an effective tracer in groundwater basin research, environmental isotopes can reveal the interrelationship between river water and groundwater. A research of groundwater and river water alongside river of Bandung area and its surrounding has been carried out. This research was conducted by taking some samples of shallow groundwater, deep groundwater and river water (Citarum, Cikapundung, Cikeruh and Citarik). The objective of this research is to determine groundwater recharge area and to investigate the inter-relationship between groundwater and river water. Based on isotopes ? ²H vs. ? ¹⁸O results, there were a mixing process at three location of shallow groundwater with river water. However, the result of isotope ¹⁴C does not show interrelationship, either by shallow groundwater or river water. From iso-age contour lines, it could be concluded that the dynamic patterns of deep groundwater show movement derived from the North and the South mountain to the North-West direction. The actual velocity in the area was around 0.25-3 m/year that can be estimated from iso-ages lines contour.