Abstract: Western exploration area of Fengfuchuan Oilfield, located in the middle-eastern part of Ordos Basin, is the multi-layer composite petroliferous region of low permeability, with complicated type of reservoir accumulation. And the development of micro structure controls reservoir enrichment of some layers. This becomes an important direction for expansion and continuous exploration in oil region. This paper is based on the analysis of micro structural characteristic, formation and evolution in the Yan 9, Yan 8 of Yan' an Formation and Chang 2, Chang 4+5, Chang 6 of Yanchang Formation which are the main oil-bearing sequences, and is based on the study of accumulation time and migration law, combined with the differences of multiple factors superposition of reservoir enrichment. And this paper shows the relationship between micro structure and reservoir enrichment. The micro structure is the nose-shaped uplift developed on the background of slope in different horizons, in which the nose uplift area developed in Yan 9, Yan 8, Chang 2 and parts of Chang 4+5 reservoir and the main sandbody superimposition part become a favorable area for migration and accumulation of oil and gas. Synthetic analysis uses the relationship between micro structure in this region and reservoir enrichment, and selects 5 favorable exploration target areas in the study area. Of the 5 favorable exploration target areas, in Ding 20 well area, Yao 304 well area, Ding 85 well area and Yao 243 well area, the tectonic uplift of both sides of the zonal range is the key zone of oil and gas exploration in the Yanchang Formation. The ancient branch valley and slope on both sides developed in the Renjiagou and Guozhuang become a favorable exploration area for ancient landform reservoir of Yanan Formation. This study can provide a reliable guarantee for oil exploration in the future.