Yanchang group of southeastern Ordos basin are tight oil accumulation conditions of the research degree is low, the tight oil exploration has not obtained the big breakthrough. To evaluate tight oil exploration prospect of southeastern basin Yanchang group, through to the sedimentary, reservoir, cap rock, oil and gas migration, such as research, in-depth analysis of the southeastern basin Yanchang group tight oil accumulation conditions. Research results show that the southeastern basin reservoir density, source store is configured, has the good geological conditions of forming tight oil.Chang6,7,8 oil reservoir group are main tight oil exploration in southeastern Yanchang group of Ordos basin. Tight oil reservoir of the formation and enrichment of Yanchang group mainly controlled by sedimentary microfacies, the high quality reservoirs. Study shows that the tight oil reservoir main accumulation period to the early cretaceous, tight oil accumulation period under the control of the late Mesozoic tectonic thermal event, has the characteristics of late accumulation.