Turkey is an important country in terms of plant species diversity due to its geographical location, geomorphological structure, micro-climate diversity, plant geography and its combination with three different flora regions. Habitat fragmentation and loss of habitat are the leading factors that threaten biological diversity. Habitat fragmentation may occur naturally or anthropogenic origin (wrong land use, road construction, forestry activities, etc.). This factor, which threatens biodiversity, causes alien species to settle in natural habitats. With 11,707 taxa in Turkey, there are also alien plant species that enter Turkey's flora in different ways such as introducing or naturalizing. It has been determined that there are 340 of alien plant species which are not included in the natural flora of our country. The Eastern Black Sea Region is a place where alien plant species can easily settle because of reasons such as climate characteristics and misuse of lands. In this study, field observations were made between 2015-2016 years in Espiye Forest Planning Unit. 19 invasive alien plant species were identified in the Espiye Forest Planning Unit. In addition to these invasive plants species, we have determined new spreading areas for the species; Tradescantia fluminensis and Oenothera glazioviana. Of the 19 invasive alien species identified, 6 are woody, 13 are herbaceous species. One of the invasive alien plants belongs to Pinidae sub-class and the other 18 belongs to the Magnoliidae sub-class. 12 of the plant species identified were recorded for the first time in Giresun province.