To explore the time course of neuroelectrophysiological activity of yin-yang analogical reasoning in traditional Chinese medicine(TCM).Methods:Event related potential(ERP) technique was used to record and compare the brain waves of 34 TCM postgraduates in judging the concrete and abstract yin-yang analogical process in TCM.Results:Behaviorally，abstract yin-yang analogies in TCM showed advantages in response time.ERP results indicated that the N400 induced by abstract and concrete yin-yang analogies as well as non-yin-yang target domains decreased successively，suggesting that the difficulty in extracting the unity of the opposites and in semantic integration increased successively.In the mapping stage of yin-yang analogies，the late positive component(LPC) induced by yin-yang analogies was larger in amplitude than that by non-yin-yang analogies，and there was no significant difference between concrete and abstract yin-yang analogy.Conclusion:The core of yin-yang thinking in TCM is the extraction and integration of the unity of the opposites.Influenced by yin-yang thinking，TCM concepts showed the convergence effect of concrete and abstract analogies in relation，which may be correlated with the double reinforcement of the metaphorical concretization of abstract concepts and the analogical abstraction of concrete concepts.