The Black Sea is an important ecosystem in Turkish marine fisheries. The early stages of economical fishes of the Black Sea can be considered well known; however, there are significant data deficiencies on ichthyoplankton assemblages and their structures. Therefore, seasonal changes of structure and dynamics of ichthyoplankton assemblages of Sinop coasts (South-Central of the Black Sea, Turkey) were investigated in this study. For this purpose monthly vertical and horizontal standard plankton net tows had been conducted at six sampling stations from two different regions (Inner and Outer Harbours) between 2002 and 2005. Species richness, diversity, abundance and similarity structures were used as ecological indicators to investigate ichthyoplankton assemblages. Planktonic stages of 27 fish species were collected during the studying period. The maximum species richness expectancy was 34 species. Seasonal changes of richness were significant (P<0.05). The groupings of similarity matrices were also explained by seasonal effects for both embryonic and larval stages (P<0.05). In conclusion, the ichthyoplankton assemblage structures of the studying area were generally shaped by seasonal spawning patterns of adult populations.