Objective: To explore the way of quantified diagnosis of blood stasis syndrome (BSS) and the essence of BSS. Methods: Using t-test and logistic regression to analyze the symptoms, signs, and objective indexes of BSS in clinical test. Results: (1) The levels of endothelin, nitric oxide, and t-PA between 182 patients with BSS and non-BSS had notable difference. (2) The stepwise regression analysis about hemoglobin, triglyceride, total cholesterol, endothelin, nitric oxide, and t-PA in 170 patients with BSS or non-BSS revealed that the order of these indexes considering their importance was: endothelin, hemoglobin, t-PA, nitric oxide. However, the triglyceride and total cholesterol could not enter the regression equations. (3) The stepwise regression analysis about 40 symptoms and signs in 601 patients with BSS or non-BSS revealed that the 18 items had the very contribution to diagnose the BSS when the F value was 6, and so a regression equation was available. The total coincidence ratio was 94.24% when the other quantified data about BSS were tested in the equation. Conclusion: The standardized TCM syndrome, which accorded with the criteria of combining diseases with syndrome,was made up of symptoms, signs, and objective indexes.The standard could be obtained by multi-center, prospective, random and controlled clinical epidemiological survey and clinical test.