Shenfu block is tectonically located in the Jinxi fold belt of the eastern Ordos Basin. where tight sand reservoirs are well preserved. such as Ben-1. Tai-2. Shan-2 and Qian-5. Rock types of these reservoirs are mainly quartz sandstone. lithic quartz sandstone. lithic feldspar sandstone. lithic sandstone and feldspar lithic sandstone. showing quartz decreasing and lithic+feldspar increasing trends from the bottom to the top. Reservoir space is mainly composed of inter-grain dissolution pore. inner-grain dissolution pore. inter-crystalline pore and microfracture. Reservoir porosity is dominated by small and micro pores. with low pore radius and medium driving pressure. The distribution of reservoir space is characterized by multi-but-thin layers and interlayers of sand-mud-coals. A gradually decreasing of component maturity and structure maturity has been discovered from the bottom Benxi Formation barrier tidal flat deposition. through Taiyuan Formation shallow delta deposition and Shanxi Formation delta deposition. to Shiqianfeng Formation braided river deposition. Diagenesis is mainly controlled by compaction. cementation and dissolution. with local kaolinization and micro-fracture. With sedimentary facies. rock type and diagenesis as three controlling end members. and porosity and permeability as criteria. Late Paleozoic tight sand reservoir in Shenfu block can be divided into four types and ten sub-types. Ⅰ-type reservoir with better sedimentary facies. strong dissolution and weak cementation is considered as the best reservoir. which has high porosity > 8% and high permeability > 0.5 mD.