ملخص البحث :

This study was conducted from January to October 2014, the samples werecollected monthly from four stations in AL-Diwaniya River at AL-Diwaniya city.Phytoplankton species which are diagnosed during study period are (506) and thenumbers of common types in four sites are (61). Bacillariophyceae is dominate onother classes and Chlorophyceae, Cyanophyceae, Dinophyceae then Chrysophyceaeand Euglenophyceae.