Abstract: Under the guidance of carbonate sedimentology and palaeontology of the theories and methods,with combination of structure and sedimentology theory of progress,and based on well logging,core,sheet and regional information,a detailed study of sedimentary facies of Upper Ordovician Lianglitage formation in well Zhonggu 3 area was carried out. The study shows that lime mud mound developed in line and zone structure along the margin of platform,the main array configuration is a developed plaster mound and bank complex, during the deposition of Liang 3 to Liang 2,plaster mound and bank complex gradually increase,reef and bank complex developed in Liang 1 formation.