In this study, the facies and depositional environments (marine, coastal, and continental settings) of the Sangachin Area (central part of the South Caspian Basin) have been investigated. In this research, two hundred and nineteen surface sediment samples were taken unsystematically in the shallow-deep areas of the Caspian seabed, coastal area and surrounding land. Sedimentary components are composed of gravel, sand and mud size particles. Six sediments types, slightly gravelly sandy Mud, gravelly Mud, muddy sandy Gravel, slightly gravelly Sand, slightly gravelly muddy Sand and gravelly muddy Sand constitute the largest percentage of all components. The components are classified into three categories: clastic (quartz, feldspar, mica, Pyroxene, and rock-fragment), non-skeletal particles (intraclast) and organic-biogenic (plant debris, marine and non-marine organisms (ostracoda, bivalves, bryozoa and Gastropoda)). The land part composed of the wetland, paleo-lagoon and marsh. The transitional and marine parts composed of the shore, the shoreface, offshore-transition and offshore, respectively. The shore zone consists of foreshore, backshore and shore dune ridges (sand dune). The non-skeletal/skeletal accumulations sub-environment has been observed in the offshore-transition and offshore environments. Rock-fragments are one of the dominant components in all identified environments (excluding offshore-transition and offshore environments). Also, non-marine bioclasts (such as non-marine bivalves Dreissea polymorpha and non-marine gastropods) in the wetland, paleo-lagoon and marsh environments; marine bioclasts (such as bivalves Cerastoderma glaucum) in the paleo-lagoon, shore, shoreface, offshore-transition and offshore environments and non-skeletal particles (intraclast) have been observed in the offshore-transition and offshore environments. Based on high-resolution shallow seismic studies in the marine area, two environments were identified: the continental shelf (shoreface and offshore-transition zones) and the continental slope (offshore zone) with stratiform and chaotic sub-bed sediments.