The Yan-9 oil reservoirs in the Yuan-72 block, Hujianshan Oil Field, northern Shaanxi are interpretated as the low-porosity and medium-permeability lithologic-structural oil pools. The oil-water recognition is based on the well logs, including intersection method, p1/2 normal probability method, and apparent formation water resistivity method. The integration of well-tie sections and planar distribution of oil and water is conducted to examine the oil- water characteristics and distribution, and will provide new information for the further development of the Yan-9 oil reservoirs, Yuan-72 block, Hujianshan Oil Field.