Rapana venosa (Valenciennes, 1846) is the only Prosobranch gastropod species which is of significant economic value on the coasts of the Black Sea and which is regularly collected in certain periods. This species, known to be of indo-pacific origin, was introduced to the Black Sea in the 1940s and it has spread over the coasts of the Caucasus, the Crimea and the Azov Sea over a period of 10 years. Subsequently, it has expanded its distribution towards the Turkish and Bulgarian coasts of the Black Sea and the coasts of Romania during 1959-1972. Rapana venosa has been reported from South-Eastern coasts of South America and also from the Red Sea and many localities of the Adriatic Sea for 20-25 years. It has been reported to be incidentally introduced into these areas probably by vessels. In this study, the ecology and distribution of Rapana venosa (Valenciennes, 1846), an invader species of the Sinop peninsula is discussed. In this context, the seasons, stations, depths and various biotopes and also the growth parameters (width-length) of the individuals were investigated depending on seasons and stations. As a result of the statistical evaluations, it was found that noticeable differences existed among the parameters examined.