Abstract: Sedimentary microfacies and reservoir heterogeneity of the turbidite sand bodies in the middle 3rd Member of the Shahejie Formation in the T74 district of Shengtuo oilfield were studied systematically based on the core observation, electrofacies analysis, well log interpretation and image analysis. The results show that the reservoir in this member is composed of three stages of turbidite sand bodies, which can be divided into two kinds of microfacies, the central microfacies and the marginal microfacies.The reservoir heterogeneity of the turbidite sand bodies is very significant, and the inlayer heterogeneity is characterized by indistinct rhythmicity and high permeability contrast. The interlayer heterogeneity and areal heterogeneity are controlled by the sedimentary microfacies, and the physical properties of sandbodies in central microfacies are better than those in marginal microfacies. The microscopic pore structure in these two kinds of microfacies is also different. The moderate pores and throats occur typically in the central microfacies, but the minute pores and throats are mainly developed in the marginal microfacies.