Three types of sandbodies were developed in the lower bitumen-bearing sandstone member of Silurian in Tazhong area ,i.e. shoreline sandbody , neritic sand bar and shelf sandbody. The shoreline sandbody deposited in normal conditions is characterized by cross-bedding with a low angular, a little ripply marker ,and the lithology cycle is from mudstone to siltstone to fine-grained stone, and than to middle-fine-grained stone from bottom to top. Under the storm background ,the shoreline sandbody mostly changes from muddy conglomerates to siltstones and fine-grained sandstones from bottom to top, with a few bioconstructions, while the low-angle cross-bedding in many directions, the hummocky cross-bedding are developed. The shelf sandbody and neritic sand bar deposited under normal conditions, are homogeneous in lithology, with reverse-graded bedding and cross-bedding being developed, grain size not changing obviously. The sediments are mainly siltstone and fine-grained sandstone. In the storm background, the rip-up of muddy gravels occur at the bottom of sandbody and grain size decreases from lower part to the upper part.. The erosional surface ,cross-bedding and hummocky cross-bedding are developed. The single sandbody of shoreline deposited in the storm background is relatively thick with thickness of 6-13m,width about several ten meters. The single sandbodies of neritic sand bar and shelf are thin, with thickness of 3-8m.Their sandbody scales are larger than that deposited in normal conditions. The distribution regulation of these three sandbodies  is obvious in space. Vertically,sandbody types change from the shoreline sandbody to the neritic sand bar then to the shelf sandbody alternately from the bottom to top ,Horizontally from marine to continent, the evolution is from the shelf sandbody to the neritic sand bar then to the shoreline sandbody.