At the North-Western Black Sea Region 36 Euglenophyta specieswere identified, relating toClass 1, 2orders, 3 families and 6genera. The greatest number of certain types belongs to Phacus Dujardand Euglena Ehrenb. In seasonal aspect Euglena ehrenbergii Klebs dominated in spring, in summer – Euglena hemichoramata (Ehrenb.) Kütz., Phacus caudatus Hübn., in autumn – Euglena deses Ehrenb. Most often and most massively euglenophytes were meti n the late summer and early autumn. In spring only sporadic isolated instances were found. With respect to organic pollution mesosaprobic group of algae was predominant therefore trophic level in this reservoir ranges from mesotrophic oeutrophic.