The natural gas reservoir of the Benxi Formation in Fuxian—Ganquan area, southeastern Ordos Basin, is mainly composed of barrier sandstone. Under the condition of a dense well network with an average well spacing of 2~3 km, drilling data revealed the vertical and horizontal microfacies combination and distributions of barrier sandbars.Methods: We analyze the distribution of sandbodies, microfacies types and combinations, profile structures, and sedimentary characteristics of the Benxi Formation barrier sandbars in the Ganquan — Fuxian area based on core, logging, outcrop, and thin section data.Results: Both the Ben- 1 and Ben- 2 Member of the Benxi Formation occured two northwest extending barrier sandbars parallel to shorelines, distributed along the slopes between ancient karst grooves and highlands. The barrier sandstone is thickened in a bead like manner, with a maximum sandstone content of about 50%, and a maximum thickness of 22 m for a single layer of sandstone. The width of the barrier is generally 3~10 km, with a length exceeding 40 km, extending beyond the study area. Under the combined action of low to medium tide and weak waves, barrier sandbars are often composed of inlet fine gravels, tidal- channel- like sands, shoal- like sands, and washover- fan sands from bottom to top. The tidal inlet is generally composed of fine- grained conglomerate and coarse to medium sandstone with a scour at the base. The tidal- channel- like microfacies located in the middle and lower parts of the barrier are mostly composed of unidirectional tabular cross- bedded and parallel bedded medium to fine sandstone, occasionally seen bi- directional herringbone cross- bedding. The shoal- like microfacies located in the upper part of the barrier sandbar are generally composed of parallel bedding and low angle wedge- shaped cross- bedded fine sandstone, occasionally seen biological disturbances, etc. Fine sandstones in washover fans generally contain mud—gravel caused by storms. Barrier sandbar change into thin interbedded sand and mudstone of tidal flat or ebb and flood tidal delta laterally, or into swamp coal seams or lagoon mudstones. There are four types of logging facies related to barrier environment: box shaped, funnel shaped, bell shaped, and toothed, with toothed and box shaped being the most common. Sandstones in barrier environments have high compositional maturity and moderate to low structural maturity.Conclusions: Barrier sandbar sandstone can be distinguished from pure tidal channel, delta, or shoal sandstone based on characteristics such as lithology, texture, sedimentary structure, cycles, and the profile and planar morphology of sand bodies.