Abstract There are several small rivers along the coast from Trabzon to Rize. The region is most rainy area of the Southern Black Sea. Therefore, in this area erosion rate about 90%. As a result of this, the rivers along the Black Sea coast transports large amount of sedimentary solid matters to the sea. In this work, 3 rivers and 1 creek runoffs to the Black Sea are studied. Transportation of suspended matter and its concentration were investigated in rivers and seawater. As it was expected, river in suspended matter concentration is high at spring and autumn. However, suspended matters are originated from marine organism and re-suspended sediments. In sea, coastal waters suspended matter concentrations are higher than open sea concentration and max. concentrations were found at near the river mouths.