Preliminary exploration prospect evaluation and screening in different areas and different exploration domain is the key to optimize exploration investment and to realize efficient exploration.Explorationists commonly select preliminary exploration targets according to such factors as petroleum-bearing property

petroleum resources

and technical and technological applicability of drilling engineering.Quantitative description of these factors and establishment of a set of unified evaluation and screening criteria are the technical challenges facing oil and gas exploration.Risk analysis-based ‘Risk Analysis-Resource Value’ model and relevant index system are established in this paper for unified evaluation and screening of preliminary exploration targets.The preferred preliminary exploration targets are ranked by the risked net va-lue.The preferred drilling targets in the 'Risk Analysis-Resource Value' model are located at the upper right of the threshold curve of risked net value which is plotted according to the number of drilling wells limited by investment.