Received 02.03.2013. Accepted for publication 14.08.2013.

Gandoman wetland is one of the main aquatic ecosystems of Chaharmahal and Bakhtiari province in the mid western of Iran. It is located close to Choghakhor international wetland. The phytoplankton diversity of the Gandoman wetland was investigated in four consequensive seasons from September 2006 to August 2007. This is the first floristic study of phytoplankton in this wetland. Six divisions of algae, Bacillariophyta, Chlorophyta, Cyanobacteria, Euglenophyta, Dinophyta and Chrysophyta had the main abundance respectively in studied sites. In total 95 species and varieties belonging to 54 genera were recorded. Bacillariophyta was presented with 51 species and varieties as the most abundant group, followed by Chlorophyta, with 18 species and 12 genera. According to this study, Gandoman wetland present an acceptable diversity of phytoplanktons according to the published alga