El- Qaa plain rises up to 200 m above mean sea level, sloping gently toward the south east of the Sinai Peninsula. It is characterized by young Tertiary and Quaternary alluvial sediments, sandstone, gypsum and limestone. Much of the alluvial sediments originated from the hills to the east, it covers an approximate surface of 6070 km2, which is estimated 10 % of the Sinai Peninsula, with a maximum length of 150 km approximately and a maximum width of 20 km. This research is aiming to detect the saline water bearing unit within the Quaternary aquifer in El-Qaa Plain area, using the vertical electrical sounding (VES) technique. This investigation based on measuring the electrical resistivity of the units with depth using the schlumberger array. In order to achieve the goal of this research, geological and geophysical studies have been executed, 30 VESes have been implemented with their processing and interpretation using Zohdy (1989) and WinSev (2004) programs. Several previous works have been collected and summarized. Hence four iso-resistivity contour maps, four cross sections, and top of saline water bearing unit contour map have been established. This study emphasizes the role of using the geoelectrical techniques in delineation of ground water quality in aquifers within such important areas.