Abstract: On the basis of the analysis test , core description data , by applying technical means such as polarizing microscope , scanning electron microscopy ( sem ), the research of petrology characteristics , diagenesis and diagenetic evolution , pore type and physical characteristics of Dongying formation in Nanpu depression has been carried out to explore the main controlling factors of reservoir development in the study area.The results show there are two major categories of main reservoir space types in Dongying formation , primary pore and dissolution pore.The dissolution pores are the important reservoir space types.Clastic rock debris and filler content composition are the intrinsic factors on the changes of pore , while pore evolution and diagenesis modification are the main external factors , among which compaction makes a poor reservoir property , while dissolution is advantageous to the improvement of deep reservoir physical properties.The most favorable reservoir type in Dongying formation is of medium porosity and permeability mainly distributed in E1 , while those in E2 and E3 belong to medium-low porosity and permeability reservoir.