The Middle Carboniferous-Lower Permian in the Tarim basin is a depositional sequence bounded by type 1 unconformites. During the depositional period of this sequence, there were three paleocontinents, two straits and a bathyal slope in the southeast part of the Tarim basin. With the eustatic change, various assemblages of paralic clastic rocks and marine carbonate rocks formed in different areas. The Middle Carboniferous Kalawuyi Formation and Azgan Formation and Upper Carboniferous Tagarqi Formation are three transgressive-retrogressive parasequence sets which make up a transgressive system tract of a second-order sequence, consisting of coastal destructive delta facies and open platform carbonate facies. The Lower Permian Pusige Formation is a progradational parasequence set pertaining to the highstand system tract, composed of fluvial-deltaic-litteral-neritic facies. The slope depositional systems have been folded and cropped out. The condensed section which formed at the end of the Late Carboniferous consists of alternating thin beds of black shale and marl 20 - 40 m thick. It can be a good oil source rock. The braided delta sand at the base of the transgressive-system-tract Tagarqi Formation and the Early Permian delta sand of the highstand-system-tract may be better reservoirs.The comparison of relatively eustatic curve of the southeast Tarim basin with that of Vail's second-grade global sea level suggests that the southeast Tarim basin was locally uplifted during the Early Carboniferous, which caused the sea level drop and stratigraphic missing. The eustatic curve of the Middle Carboniferous-Early Permian are correlable with the global one.