The present study aimed to investigate the non-diatomic algae community and some biodiversity indices in the Hilla River during the study period from October 2018 to July 2019 for three sites along the Hilla River. Physicochemical parameters of water quality assessment and the phytoplankton population is measured using a sedimentation technique identified mainly using some diagnostic sources. Where a total of (48) genera and (100) species were diagnosed, belonging to 5 classes as follows: Chlorophyceae (23 genera, 59 species), Cyanophyceae (16 genera, 30 species), Dinophyceae (4 genera and 4 species), Chrysophyceae (3 genera, 5 species) and Euglenophyceae (2 genera and 2 species). The highest and low values recorded for biodiversity were (1.9 and 2.9) at site 3 and 1, respectively, while the richness index ranged between 43 and 48, and the highest value for numerical Evenness Index was (0.77) at site 3 and the lowest values (0.51) at site 1 and 2, Simpson dominance index has recorded the highest value (0,272) at site 1 and 2 and the lowest values was (0.122) at site 3. Canonical Correspondence Analysis (CCA) was used to estimate the relationship between environmental factors and algae, water temperature (water temp.) salinity, pH, chloride, and alkalinity were important factors influencing the distribution of phytoplankton community.