Öz Among The Boyabat Basin’s deposits, there are some units reflecting petrolcüm source rock appereances. Our target has been determînations of Kusuri and Çağlayan formations sour­ ce rocfc potentials. A research, inciuded of petrolcüm source rock, has no been carried out tîll now. Deposits in the basin have flish characters in general but it is also possible to observe car- bonates inciuding volcanic matters. In order to detenaine source rock specifications of the area, measured stratîgraphîcal cross- section were drown and systematic samples were collected. A number of analyses, such as orga- ganic carbon amount, pyrolise, organîc matter type, maturity and clay X-ray difractometer analyses, were applied on the shale samples. According to the analyses results, keregone types are Tip II and Tip III, there are sufficent amount of organîc matters, maturity is good enough to give petrolcüm and gas. As for the Kusuri formation, due to low amount of organîc carbon and staying in limited area. It is not determinated as a petrolcüm source rock.