Abstract: Core competence of large oil corporation is a guarantee of national oil security，the forming of which is influenced by various factors.Based on the analysis of the status quo of core competence of large oil corporations，the authors suggest that an innovative 3dimentional(Resources，Competence，and Innovativeness) and multileveled evaluation mode will work more accurately in core competence evaluation of large oil corporations.The new model takes the relation between corporate competence and most optimal point of core competence as the measure of core competence of large oil corporation.And application of this model reveals that the closer corporate core competence is to the most optimal，the stronger core competence corporations have and the better adjusted they are to the environment and vice versa.

Key words: large oil corporations, core competence, resources, competence, innovativeness, evaluation model