In this study, firstly, the shoreline changes for various wave heights, wave periods and angles have been investigated on straight and curved beaches. The "One Line Model" of Hanson and Kraus which determines the shoreline changes by explicit finite difference numerical model, has been utilized. Subsequently, this numerical model has been applied to the shores of Altmova Town in Balikesir, Turkey. Altmova has a valuable coastal zone that is located on the Aegean Sea with a coastline miming more than 13 km and has a very high potential for tourism. It has been assumed that sediments are transported along the shore due only to the sea waves. In order to evaluate bathymetric changes and shoreline movement in the Altmova coast, hydrographic measurements were made in August 1996 and December 1997. In the nearshore region coastal erosion has clearly been predicted by comparison of numerical model results and data obtained by field measurements. Coastal structures have been suggested to protect against erosion.