Abstract: In this study, the occurrence of Sirelina orduensis Meriç and înan (1996) in Upper Maastrichtian levels in the different outcropsof Ilgaz (Çankırı) region was discovered. Sirelina orduensis was described first time by Meriç and İnan (1996) in Gölköy formation(Ordu).Sirelina orduensis Meriç and İnan different from other foraminifera by their microgranular test structure, different coil according their development stages and lateral orbitoidal chambers.This species was discovered abundantly in Upper Maastrichtian aged sandy limestone levels of Ödemiş formation (Pehlivan etal, 1987) crop out at Ilgaz (Çankırı) region which was represented by sandstone, sandy limestone, limestone and claystone.