Analogy is one of the important philosophical thoughts of traditional Chinese medicine,and makes an important contribution to the formation and development of theory system of traditional Chinese medicine. With the development of modern life science,analogy in traditional Chinese medicine also has a new connotation. This paper attempts to use the modern life science terminology to elucidate the new understanding of analogy based on theory of yin-yang and concept of “fighting poison with poison”,and further explores the value of analogy of traditional Chinese medicine in the life science research and discovers the potential scientific logic,in order to guide and explore new scientific phenomena and solve key scientific issues in life sciences and medicine.