Abstract: Analysis of oil reservoir microfacies is important for the study of remnant oil and the anisotropy features of oil reservoir in later period. Based on the core analysis, and the study from genesis facies to combination and genesis analysis of genesis facies, from building loggings microfacies mode to the analysis of single logging facies, and to the analysis of plane microfacies, the author studies the subdivision microfacies of Yan 9 oil reservoir in stream facies in Fanjiachuan oil field, and using the method of mode-protracting to analyze the combination of plane microfacies.The study makes a solid geological foundation for the further development of later remanent oil.