The unconfined aquifer in the study area overlooks the Gulf of Aqaba; this classifies it as a coastal aquifer. All over the world, coastal aquifers are considered as an important source of water, with the fact that, many of coastal areas are heavily analyses; the need for fresh water becomes even more acute. Encroachment of seawater towards the groundwater body is a kind of pollution with respect to the groundwater; it inherits the groundwater higher salinity. This leads us to evaluate and assess the vulnerability of the unconfined aquifer in study area against pollution using certain method such as DRASTIC index by using GIS. And then dividing and categorizing the area according to vulnerability degree, to be able to prevent any pollution could be happened to the ground water and to the sea water by sea water- ground water contact, therefore the area should be divided according to its vulnerability level using DRASTIC index in geographic information systems to obtain on 70% low vulnerable zones and 30% moderately vulnerable zones.