This study aims to assess surface and groundwater availability in Dong Nai river basin by integrating SWAT and MODFLOW models. These models run individually and integrated through the recharge rates. The simulation results were then compared and showed good agreement with observed data. The results showed Tuyen Lam, Da Huoai and Dak Song districts are the locations which have high surface water availability, in the range of 40 - 50 l/s/km2 . | Integration of swat and modflow model to assess the surface and groundwater availability A case study of Dong Nai basin in 2015-2016