Abstract In the present 'study carried out between July 1997 and June 1998, samples of macrobenthic fauna were collected at Akliman (Sinop) where Sirakaraagaglar stream flowed into the Black Sea. The physical parameters of water were measured, Sea, brackish water and fresh water species were determined, 39 in total including Mollusca, Insecta (larvae), Crustaceae, Polychaeta, Hirudinae and Turbellaria, The first. sampling station was chosen at the mouth of the Sirakaraagarlar stream. The results show that the Mollusc Fauna was predominant in respect to species diversity, while the species belonging to Insects larvae, Crustaceae and Polychaeta Classis were in minority. The second and third stations were chosen at the inner place from the mouth of Sirakaraagaclar stream near its spring. Insecta larvae was predominant in respect to species diversity, whereas the species belonging to Mollusca fauna, Crustaceae, Polychaeta, Hirudinae and Turbellaria Classis were in minority. Thus, the most predominant species in Sirakaragaglar Stream were identified as euriform and found in less flowing part of the stream.