Many symbolic structures used in religious and philosophical traditions are composed of “elements” and relations between elements. Similarities between such structures can be described using the systems theoretic idea of “isomorphism.” This paper demonstrates the existence of a near isomorphism between two symbolic structures: the Diagram of the Supreme Pole of Song Neo-Confucianism and the Kabbalistic Tree of medieval Jewish mysticism. The similarities of these two symbols in form and meaning are remarkable in the light of the many differences that exist between Chinese and Judaic thought. Intercultural influence might account for these similarities, but there is no historical evidence for such influence. An alternative explanation would invoke the ubiquity of ideas about hierarchy, polarity, and macrocosm-microcosm parallelism, but this does not adequately account for the extent of similarity of the symbols. The question of how to explain their resemblance remains unresolved.