Abstract: Chang 8 reservoir of Honghe oilfield in Ordos basin is a typical tight sandstone reservoir with poor physical properties and developed natural fractures.The exploration and development practice for many years has proved that the development degree of faults and fractures plays an important role in oil and gas enrichment and efficient development of Honghe oilfield.According to the fracture characteristics,types and genesis of Chang 8 reservoir in Honghe oilfield,the reservoir fracture is finely described,and the formation mechanism and distribution law of reservoir fracture are clarified.Through systematic analysis of the relationship between the fractures and the enrichment of oil and gas in Chang 8 reservoir,the influence of the fractures on the development and production of Chang 8 reservoir in Honghe oilfield is clarified.The results show that the fracture of Chang 8 reservoir in Honghe oilfield is developed,but its effectiveness is poor.Among them,fracture development areas at the end of fault,hanging wall of fault and between faults are favorable areas for high production.The natural fracture is the main reservoir space and seepage channel of Chang 8 reservoir,the key factor for controlling oil well productivity,and also the important factor for affecting reservoir water injection development.