Continuous hydrocarbon reservoir is an important type of hydrocarbon accumulation. Determining its distribution borders is significant for oil petroleum exploration. Based on analysis of continuous reservoirs found in domestic and overseas，the characteristics of hydrocarbon enrichment in the fourth member of Shahejie Formation were determined according to actual geologic conditions in Bonan area. The method for determining the type of hydrocarbon reservoir was provided through analyzing the formation mechanism of the continuous hydrocarbon reservoir. The study results show that widely dis? tributed source rock with high-quality，high formation pressure for hydrocarbon generation and continuous tight reservoir are the main characteristics of continuous reservoirs. The fourth member in Bonan area in the centre basin-slope has the geological conditions for continuous hydrocarbon reservoirs formation. The hydrocarbon accumulation could be seen as “pressure in source rock decreasing while hydrocarbon expelling and pressure in reservoir reconstructing while hydrocar? bon charging”. The minimum values of physical properties of reservoirs when hydrocarbon charging could be calculated by the relationship between the hydrocarbon generation pressure and capillary resistance，and the maximum values could be calculated by the pressure difference of continuous oil column and the relationship between the buoyancy of oil column and the capillary resistance at the top of the oil column. A method for calculating the minimum and maximum value of the property was put forward according to the recognition. The porosity of the hydrocarbon reservoirs is 2%-11% calculated by this method and errors would be made since its accuracy may be affected by the quantification extent of pressure，porosity and resistance. The calculated results will be more closed to the actual geological condition when the quantitative model of the influencing factors is improved.