Abstract: The Kelamayi Oil Field has well-developed reservoirs and abundant oil and gas resource at Block 8 in the Keshang Formation. Based on the core and log data, the sedimentary.microfacies of group S4-S5 of Ke-shangare formation are fully studied according to log-facies analysis. Then the sedimentary microfacies distribution features are plotted and the distribution and evolving discipline are analyzed comprehensively. As a result, it formed a firm geological basis for reservoir description and geological model foundation.