Soganli Formation of Early Eocene age in the northeastern of Arac (Kastamonu) has been investigated in order to determine their paleontology and palaeoecology. The sequence consists of gray, yellowish, clayey limestone, rich in larger benthic foraminifers. The lower parts of clayey limestone are dominated by porcellaneous foraminifera such as Alveolina and Orbitolites and by dascylad algae. The top of the section is characterized by hyaline calcareous foraminifers such as Assilina and Nummulites. Idalina sinjarica Grimsdale, Glomalveolina lepidula Schwager, A. cemali Sirel & Acar, A. rotundata kazancii Sirel & Acar, A. erki Acar, A. ankarensis Sirel, A. pieroi Sirel & Acar, Lockhartia conditi (Nuttall), L. tipperi (Davies), Orbitolites complanatus Lamarck, Cyclopertorbitolites tokerae Ozgen-Erdem, Assilina spinosa Davies & Pinfold, Nummulites sp., Cribrobulimina sp., Kathina sp., Neorotalia sp., Triloculina sp. have been decribed along the section. The distribution of the larger benthic foraminifera indicates Early Eocene age. According to these assemblages, we interpret that deposition of the unit started in a restricted shallower environment and continued in a shallow high energy environment.