The upper-plate Carboniferous of the Ke-Bai fractured zone were studied for revealing some key problems about the distribution of the favorable reservoirs, pool-forming pattern and reservoir types. The favorable reservoirs were controlled by faults, fractures and long-time weathered and leached regions. The permeability of reservoirs was controlled by the enrichment degree of micro fractures, which mainly distributed in the region from two to three kilometers near the faults with the spaces of 2-5 kilometers. So, the lithological aspect did not affect the distribution of favorable reservoirs. The favorable reservoirs covered the whole fault belt and best developed in the faults. The rebuilt pool-forming patterns and reservoir types showed the regularity of oil and gas abounded along the fault belts and changed the understanding about the reservoir type from fault-lithologic type to large lithostratigraphic type. The whole fault belt was considered as oil-bearing region. The new understanding improved the increase of exploration range in this area. In recent three years, the proved reserves of Ke-Bai fractured zone are more than the total reserves in the past 50 years.