Understanding north Java coastal aquifer system: evidence from Kendal, Mid Java Introduction Java Island is one of the most populated island in Indonesia, especially at the coastal area which usually has a great access and scenery with flat stable terrain condition for a big suitable city to be built above. Kendal Regency, which located in Mid Java Province, is one of the newly-developed town in the coastal area, and as it still in the development phase in which more water will be needed for the activity. It is known that surface water could not be used enough to fulfill the daily human water needs due to its poor quantity as well as quality. Therefore groundwater is needed to support it. Exploration of groundwater resources must be carried out to recognize and evaluate the characteristic, geometry and potential of groundwater resources in such area for optimum supply which will be very useful for further sustain town planning and development. The measurement exploit a combination between geological and field geophysical measurement data, to recognize the groundwater bearing rock (known as aquifer rock layer) in the research location. The geophysical measurement in this research using electricity properties as a parameter to determine the location and distribution of an aquifer below the ground. The specific objectives are to evaluate hydrogeological parameters, determine the aquifer and aquitard position, model, and predict its distribution.