Natural and unnatural factors would develop coastal areas. Coastal area is a region that takes materials and substances from land surface then transfers them to sea and the remained and cumulative substances of them would deform under the effect of erosion forming the coasts appearance. Geomorphology is the study of land and process leading to formation and development of it. Coastal geomorphology emphasizes on formation of coastal areas and some processes such as waves, tides, and stream leading to formation of boulders, coral reefs and sandy beaches. The base of this study is on analytical comparison method of affecting variables on periodic change of shoreline in river estuary in which statistical and image data were analyzed. This research was conducted within three time intervals including 1955-1988, 2000-2006, and 2006-2013. Wind hourly data of Meteorological Organization of Iran was used to study waves. The fluctuation in level of Caspian Sea is an important factor in changes in shoreline of Caspian Sea besides the role of river and providing sediment output into the sea. The most area was belonged to 1995 along with declining trend of seal level of Caspian Sea and the lowest area was belonged to 2000 with a rising trend of sea level within three studied intervals. This point indicates the effect of seal level factor on change in area of studied intervals.