RESUMEN
Since the theory of microcosmic syndrome differentiation was put forward in 1986, Chinese medicine academia has been unremittingly exploring this theory. Efforts were made to explain the syndrome in Chi-nese medicine with objective index of modern medicine, so that different syndromes of the same disease can be rec-ognized on the quantitative view and then apply syndrome differentiation with objective index. This paper compre-hensively analyzed and got the primary causes why microcosmic syndrome differentiation was difficult to apply. It in-cluded no-identical criterion, research design such as the choice of syndrome, reference syndrome, objective index and microcosmic level. Additionally, too many virtual syndromes resulting from applying syndrome differentiation on western medicine diseases existed widely. Consequently, it is extremely urgent that solve these problems and regulate the research thought.