Abstract: According to analyses of cores, thin?sections, imaging logs and outcrops information, nine microfacies and classified as four microfacies sequences within the Yingshan formation of Late Ordovician in central north slope of Tazhong uplift in Tarim basin were recognized. There existed four types of reservoir spaces in Yingshan formation, which are dominated by fracture?vugular pores, followed by small vugular pores, seldom fractured and vuggy spaces. The result shows that the high energy microfacies sequence is the primitive materials for the favorable reservoirs, easily forms small vugular pore and fracture?vugular types of reservoirs, and these several types of reservoirs overlap followed by shaping the high quality reservoir. The low energy microfacies sequence occur as undisturbed formation or barriers, but it could produce local bits of fractures and vugular/dissolution pores, which may form relatively small?scale fractured and fracture?vugular pore types of reservoirs in this area