In the Upper Cretaceous of North-Eastern part of Volyn-Podillya there are defined two periods of sedimentation: Early-Late Cenomanian and Late Cenomanian-Santonian. The first one characterized by accumulation of glauconite-quartz and phosphate-glauconite-quartz terrigenous sediments, fine gravel admix and siliceous cementation. Late Cenomanian-Santonian period characterized by widespread carbonate and carbonate-clay sedimentation. In the Phd Work we monographically described 81 species that belong to 23 families. Firstly for the territory of the North eastern Volyn-Podillya there were defined 47 upper cretaceous bivalves species, 13 of which were found on the territory of whole geological region for the first time. Two of the found species are considered to be new, not described anywhere. In the Upper Cretaceous deposits there were differentiated 8 complexes of bivalve, among which Early and Middle Cenomanian were the most representative according to number of species. From an Early Cenomanian to Early Turonian, the researched territory belonged to a vast Epicontinental sea basin, divided by islands of various size. Such situations where in Campanian and Maastrichtian. From Middle Turonian to Late Santonian, the territory was completely covered by sea. There were set three rising zones: the area of basalt massifs in the northern-east and central part, Ukrainian Shield in the east and Paleozoic rocks highland in the south. In the Upper Cretaceous of North-Eastern part of Volyn-Podillya there are defined two periods of sedimentation: Early-Late Cenomanian and Late Cenomanian-Santonian. The first one characterized by accumulation of glauconite-quartz and phosphate-glauconite-quartz terrigenous sediments, fine gravel admix and siliceous cementation. Late Cenomanian-Santonian period characterized by widespread carbonate and carbonate-clay sedimentation. In the Phd Work we monographically described 81 species that belong to 23 families. Firstly for the territory of the North eastern Volyn-Podillya there were defined 47 upper cretaceous bivalves species, 13 of which were found on the territory of whole geological region for the first time. Two of the found species are considered to be new, not described anywhere. In the Upper Cretaceous deposits there were differentiated 8 complexes of bivalve, among which Early and Middle Cenomanian were the most representative according to number of species. From an Early Cenomanian to Early Turonian, the researched territory belonged to a vast Epicontinental sea basin, divided by islands of various size. Such situations where in Campanian and Maastrichtian. From Middle Turonian to Late Santonian, the territory was completely covered by sea. There were set three rising zones: the area of basalt massifs in the northern-east and central part, Ukrainian Shield in the east and Paleozoic rocks highland in the south. Key words: bivalves, Upper Cretaceous, Volyn-Podillya, stratigraphy, biostratigraphy, lithostratigraphy, paleogeography, paleoecological conditions.
