Soc Trang province, a coastal province of the Mekong Delta (MD), has been using groundwater for water supply since more than ten years. Due to the over exploitation of ground water resource, the recent monitoring has shown a significant draw-down trend of groundwater table in aquifers, especially in the Pleistocene aquifer. However, there is still lacking of assessment tool for groundwater capacity in the MD. Mathematical models are very essential in water resources management in general and particularly in groundwater management. There are some groundwater modeling have been conducted in the MD. These models applied MODFLOW software to simulate the steady state of ground water. The results from these models are maps of piezometric contour and flow directions, inventories of water balance. However, as the models were carried out at regional level, a detailed analysis for provincial level is necessary. This paper presents an application of iMOD groundwater model in Soc Trang province. The model provides an interactive ground water assessment tools in which information support for water management decision such as ground water level dynamic due to different exploitation scenarios can be defined.