Shorelines are important boundaries separating the erosional and the depositional areas. Determining the location of the shorelines in geological time sand how it changes by the time is one of the major problems of geology. The most accurate estimate of the location of the shoreline, which is a dynamic structure, in the period when it was exist is very important in palaeogeographic studies. The determination of coastal changes by the time provides valuable information on active tectonic sand climate, and the relationships between these two. The most basic approach to determine the paleoshoreline is to estimate the geological events on the sea and land sidesand thus to estimate the location of it indirectly. For this purpose, if the physical, chemical and biological conditions of the depositional environments from land to shore and from there to the basin and which land part and how fed this environment can be revealed, the location of the shoreline can be estimated. Incontrast, some field observations provide direct and much more precise data for identifying the paleoshorelines. In this paper, it will be introduced how somerock-boring organisms, wave-cut feature sand coastal sediments can be used to estimate the paleoshorelines based on two examples of Quaternary sediments in Hatay and Rhodes Island along th Mediterranean coastand on some Eocen esediments in the vicinity of Corum, Central Anatolia.