Abstract: The confusion on the sedimentary microfacies distribution and evolution law of the C-6 oil formations in Block L of Jingbian Oilfield has long restricted the development of oil reservoirs. Based on the dense well data, core and grain size analysis, the paper comprehensively studies the markers and types of sedimentary facies and distribution and evolution law of microfacies to establish the sedimentary models of the study area. The results show that the C-6 reservoirs are mainly delta plain deposits with the sedimentary microfacies of distributary channel, natural levee, flood plain and marsh.