Integrated analysis of western margin outcrop, core and well-logging, seismic data and analytic data in Tarim Basin，five sequences with thickness of 40-155m have been identified in Silurian. Each sequence consists of either complete lowstand, transgressive and highstand systems  tracts or one or two of them. Pattern of Silurian in Tarim basin may be described by type I sequence model with shelf break. Sequence boundaries are mainly wide spreated regional or local unconformity; boundaries of systems tract are mainly decided on onlap location, lithologic association and variations of parasequence patterns. Lowstand systems tract consists of parasequences with fining in grain size and thinning in sandstone thickness upward; transgressive systems tract is characteristic of thinning in sandstone thickness and thicking of mudstone thickness upward; highstand systems tract is characterized by acceleration - progradation sedimentation. Sedimentary types of Silurian are mainly of shelf , offshore, and flat with typical marine sedimentary structures and cycles vertically.