Abstract: Abstract：Fuwan and Zhangchang Area is located in the center of north clinoform zone in Biyang Depression，which is of pos-
sibility to become a subtle reservoir，as a result of inconspicuous positive structure，growth of fault block architecture and fairly
growth of sandstone lithology. Taking reservoir group IV—VI for example，combining with core observation，well logging，
grain size and areal geology information，this paper establishes a model of beach-bar in study area，when sedimentary charac-
teristics and dimensional distribution discipline of beach-bar facies is determinate. First，the main lithology is fine sandstone，
siltstone and pelitic siltstone in study area，and logging trace is like egg with symmetric transition and funnel with converse
circle，and grain probability curve is two-stage with no roll components mostly，and the main sedimentary structure is wave
bedding and cross bedding，many biological burrows and much commotion structure included，and depositional sequence is
mainly adverse facies sequence，besides，beach facies and bar facies are symbiotic，and vegetal area has strong compatibility.
Second，bar facies grows in IV—VI Group，especially in IV Group. Beach facies just grows in a few wells in V Group in a
small way.

Key words: Key words：Biyang Depression, bar facies, beach facies, sedimentary characteristics, sedimentary model