Morphological changes of river Atrak a period of 20 years

River boundaries، international boundaries are one of the variations and deviations canal beds، the problems and tensions between the countries forming the delimitation. Atrak River for various reasons، including putting on the erosion of geological formations، human activities such as land use changes and the morphological changes. In this study، the morphology of the river Atrak range approximately 150 km sumbar the junction of the branch to the Caspian Sea has been studied. Using TM and ETM satellite images in 1994، 1999 and 2013 timeframe river Atrak 3 of sensing distance using ENVI software were extracted. Geometric parameters such as the length of the river، wavelength، and index of curvature، central angle and arc tangent circle fitting method for assessing changes in river environments do Auto Cad software comparison in the change has been studied. Comparison of geometric parameters meander arches and desire for the third period، the changes in certain arc and thus suggests that river channel morphology and instability. In the villages tarshekli and dashlibron around the river has changed course so that the tarshekli village change will benefit Turkmenistan and around the village of dashlibron out in favor of Iran. These changes are due to the erosion of the river bed and banks. As a result، it becomes clear that Atrak river bed and channel are changed and the change of the type of geological formation، formation of erosion along the river bed، bed sediment load increases، changes in water flow، human factors and the erosion of adjacent is related rivers.