Algae can be used as indicator for water quality, which could be a benefit for fish health. In this study, algae and water samples were taken from three selected stations from Keban Dam Lake Gülüşkür Region were investigated for six months between March 2015 and August 2015. A total of 48 taxa belonging to Chlorophyta were recorded during the study. Members of Chlorophyta showed their best growth in July and August, when light and temperature increased. Species belonging to Scenedesmus, Pediastrum, Ankistrodesmus and Oocystis genera were the most important members of phytoplankton with their frequency of occurrence and the size of the populations they formed.