The reservoir in the middle submember of the third member of the Shahejie formation in Pucheng oil field is extra-low in porosity and permeability. The analysis of intraformational, interlayer, lateral and porosity heterogeneities indicates that the reservoir is high heterogeneous. And this study also proves that theheterogeneities are controlled by the sediment process and diagenesis. Braided channel, always becoming worse from base to top, is more strong in heterogeneities than inter-channel and sheet-like sands which are always with a trend of becoming bad from bottom to top inside sand. The heterogeneous factors of medium and short term cycles indicate its high intra- and inter-layer heterogeneities.There are two main directions the sand developed:north-east and south-east, of which the north-east is main. The braided channel are high in permeability and the inter-channel and sheet-like sands are always low in permeability. The porosity throat analysis indicates a narrow throat, of which narrow than 1 μm throats make the main part. 