The Upper Carboniferous Taiyuan Formation is a characteristic coal-bearing measure interbedded with terrigenous siliciclastic and carbonate rock in the Shenmu Gasfield of northeastern Ordos Basin, central China. Recent exploration testified its good potential for next gas development. To offer guidance for Taiyuan Formation exploitation in this gas field and exploration in Ordos basin, the strata assemblages, sedimentary characteristics, environment evolution, sandbody width and sedimentary facies control on reservoirs of Taiyuan Formation are investigated based on analysis of well-logging, mud-logging, routine thin-secition, cast thin-section, routine petrophysical property and grain size and combined with core description. The Taiyuan Formation develops three types of strata assemblages, including clastic rock type, limestone type and interbed of clastic rock and limestone type. The color, grain size, composition, texture, sedimentary structure, lithofaices, log facies, inclusion and depositional succession of Taiyuan Formation indicate it deposited from tide-dominated delta and low-energetic carbonate platform, mostly from environment of deltaic plain distributary channels and interdistribuarty swales, deltaic front distal bars and underwater interdistribuary bay, and lime tidal flat and lime-mud tidal flat. The lower portion of Taiyuan Formation (the Second Member of Taiyuan Formation, briefly SMTF) is mainly controlled by deltaic plain deposits, of which distributary channel sandbody is wide spread but has relatively narrow width(7.1-131.9m). The upper portion(the First Member of Taiyuan Formation, briefly FMTF) deposited from deltaic front and carbonate tidal flat. This implies the Taiyuan Formation had passed through a transgressive process with gradually water-depth deepening and/or a depositional process with gradually clast support decreasing. The interbed of clastic rock and carbonate rock in the FMTF reflects an oscillating process from water-depth deepening to shallowing and/or a kind of cycling insufficiency of terrigenous clastic supply. The reservoirs mostly exist in the medium-and coarse-grained sandstones deposited from high-energetic deltaic plain distributary channels in the SMTF.