Abstract: Jurassic stratigraphy is newly discovered near Mengang Cuo at Quluo Township,Cuoqin County,Tibet.The measured Jurassic section is described in details in this paper.It is temporary named as Quluo Formation.Lithological association and sedmentary environment of Quluo Formation have been discussed .The sedimentary environment are mainly composed of trasitional delta facies to coastal region lagoon.The time age of Quluo Formation is believed to be Early Jurassic according to bivalve fossils,plant fossils and sore-pollen association. The discover of Lower Jurassic in Cuoqin area will provide new data on area tectonic evolution and exploration of mineral resources.