Abstract: In the present paper, the Middle Jurassic Buqu Formation section containing asphaltum vein is studied in the Gongri area, eastern part of Qiangtang basin, Tibet，nine main types of carbonate micro-facies are distinguished in the deposits. They are lime marl, lamellar power-micrite limestone, calcarenite, pellet micrite-sparite packstone，oncoid lump packstone，bioclastic packstone, bioclastic wackstone, oosparite grainstone, bioclastic line marl. According to microfacies assemblage and sedimentary structure, carbonate rock of Buqu Formation mainly form three sedimentary environments: inner ramp, middle ramp and deep ramp. Four sedimentary cycles are recognized in the Buqu Formation, which constitue of a transgressive sequence, which is composed of entire sea-level cyclic sequence.