Ibn-Najem marsh is one of the Iraqi Marshlands that occupies around 90 Km2 distributed in three provinces. However, the majority of the marsh (75%) belongs to An-Najaf province, the rest of which is shared by Babylon and Al-Qadisiyah provinces' . The concentration of iron , manganese and phytoplankton biomass as chlorophyll were measured in winter, spring, summer, and autumn in 2009 in water and sediments of Ibn-Najem marsh. Phytoplankton were collected from seven sampling stations including Al-Haidarey, Abu Garab , Um Oyon , Al-Tail , Al-Gazali, Abu-Hallan and Al-Hamam respectively. Iron and Manganese ions were measured in water and sediments. The average rates of phytoplankton biomass were high in station 3 in spring with a value of 0.49 μg/l as the results indicated. The minimum value was found in station 1 in winter with a value of 0.03 μg/l .The concentration of manganese was extremely high in the sediments, while the concentration of iron was low in winter and autumn . Iron decreased in the sediments in winter, while in water, it recorded minimum values for iron which was measured in summer. The maximum values of iron and manganese were noticed in autumn. The minimum concentration of manganese was in spring. The concentration of iron and manganese elements exceeded than Iraqi limitations for freshwater quality.