The Taiyuan Formation is dominated by shallow water delta deposits in a north uplifting and south inclining tectonic setting. Its characters are as follows: when the sedimentscarrying river flew into the seawater， due to the different density between river and seawater， and a little latteral diffusion， the delta front would move along the seabed rapidly， and the subaqueous distributary channel extended a long distance. The study area is characterized by a gentle slope and shallow water setting， thus the delta plain extended forward and decreased the topographic slope furthermore which led to the decrease of energy of fluids carrying the sediments and most of the sediments were deposited in the distributary channel in the  delta plain. Otherwise， due to the shallow water setting， mouth bar and sheetlike sandbodies of delta front were easily exposed by the transgressive subaqueous distributary channel and were difficult to be preserved. Distributary channel was well developed， prodelta was relatively not well developed and delta front was dominated by subaqueous distributary channel deposits. Distributary channel and subaqueous distributary channel usually strongly eroded the underlying sediments， including the sediments deposited during early periods even the deep water sediments including marine sediments. During the abandonment period of delta， sediments of delta front were usually rebuilt by tidal action. Distributary channel sandbodies of delta plain and subaqueous distributary channel of delta front are distributed in belt  which are the favorable targets for natural gas exploration.