Submerged notches that indicate negative sea level change evidence during The Quaternary. Through their study, the effects of sea level change and effect of tectonic lifting movements on them during the Quaternary are identified. Submerged notches as negative evidence below MSL are studied in the field work in two areas: The first one is "San Foca" area that comprises three parts from north to south:" Torre di Roca Vecchia bay" and "Madonna di Roca Vecchia bay", the second area is "Castro", only "Porto Castro" is studied below the current sea level. The studied area located in the Ionian Sea coast, South Italy, its total length is about 53 km. The studied area is the south-east part of the Apulia region (southern Italy), stretching between the Ionian Sea and Adriatic Sea. It is located on the east coast of the Salento peninsula. Its coordinates are 40˚ 0´ 2.43˝ to 40˚ 18´ 6.85˝ N, and 18˚ 16´ 10.10˝ to 18˚ 31´ 30.99˝ E The aims of this paper to define the effects of the Quaternary Sea level change on submerged notches, and study the evolution of coastal karst in current climate conditions. The methodology of this study depended upon extensive field and measurements of submerged notches, an in addition to GPS.