The East Sakhalin accretionary wedge is a part of the Cretaceous-Paleogene accretionary system, which developed on the eastern Asian margin in response to subduction of the Pacific oceanic plates. Its for� mation was related to the evolution of the Early Cretaceous Kem-Samarga island volcanic arc and Late Cre� taceous-Paleogene East Sikhote Alin continentalmargin volcanic belt. The structure, litho�, and biostratig� raphy of the accretionary wedge were investigated in the central part of the East Sakhalin Mountains along two profiles approximately 40 km long crossing the Nabil and Rymnik zones. The general structure of the examined part of the accretionary wedge represents a system of numerous eastvergent tectonic slices. These tectonic slices. tens to hundreds of meters thick. are composed of various siliciclastic rocks, which were formed at the convergent plate boundary, and subordinate oceanic pelagic cherts and basalts, and hemipelagic siliceous and tuffaceous-siliceous mudstones. The siliciclastic deposits include trenchfill mudstones and turbidites and draping sediments. The structure of the accretionary wedge was presumably formed owing to offscraping and tectonic underplating. The offscrape d and tectonically underplated fragments were proba� bly tectonically juxtaposed along outofsequence thrusts with draping deposits. The radiolarian fauna was used to constrain the ages of rocks and time of the accretion episodes in different parts of the accretionary wedge. The defined radiolarian assemblages were correlated with the radiolarian scale for the Tethyan region using the method of unitary associations. In the Nabil zone, the age of pelagic sediments is estimated to have lasted from the Late Jurassic to Early Cretaceous (Barremian); that of hemipelagic sediments, from the early Aptian to middle Albian; and trenchfill and draping depo sits of the accretionary complex date back to the middle-late Albian. In the Rymnik zone, the respective ages of cherts, hemipelagic sediments, and trench facies with draping deposits have been determined as Late Jurassic to Early Cretaceous (middle Albian), mid� dle Aptian-middle Cenomanian, and middle-late Cenomanian. East of the rear toward the frontal parts of the accretionary wedge, stratigraphic boundaries between sediments of different lithology become succes� sively younger. Timing of accretion episodes is based on the age of trenchfill and draping sediments of the accretionary wedge. The accretion occurred in a period lasting from the terminal Aptian to the middle Albian in the western part of the Nabil zone and in the middle Cenomanian in the eastern part of the Rymnik zone. The western part of the Nabil zone accreted synchronously with the Kiselevka-Manoma accretionary wedge located westerward on the continent. These accretionary wedges presumably formed along a single conver� gent plate margin, with the Sakhalin accretionary system located to the south of the Kiselevka-Manoma ter� rane in the Albian.