Following the principle of Syndrome study in TCM, parallel control groups were set up according to "the same disease with different Syndromes" and "different disease with the same Syndrome", the significance on deformability of red blood cells and peripheral microcirculation analysis in "disease" and "Syndrome" diagnosis were explored. Results showed: the both parameters were not characteristics of "disease" diagnosis, but were characteristics of "Syndrome" diagnosis. It suggested that: both "disease" and "Syndrome" reflected pathophysiological state of human body in disorder, and "Syndrome" is a highly condensed expression of this status.