Objective To explore methods to determine syndrome diagnostic criteria using Dachaihu Decoction as an example. Methods A case-control study based on literature was conducted. Clinical cases with the prescription similar to Dachaihu Decoction（ the similarity ≥ 0. 75） were chosen as the case group. Taking the diseases treated by Dachaihu Decoction in medical treatises as mixing ratio factors

cases with the same diseases were chosen as the control group. A database based on the information of the collected cases

diseases treated in the control group

clinical manifestations and other information was established. Single factor analysis and Logistic analysis were applied on clinical manifestations. And on this basis

syndrome diagnostic criteria for syndrome of Dachaihu Decoction was determined by ROC curve analysis. Results Seventeen indicators were screened out by single factor analysis of clinical manifestations

among which

alternate attacks of chill and fever and fullness and discomfort in chest and hypochondrium held the highest scores. Logistic analysis dedicated a scale including 8 indicators. According to the covariance coefficient（ B）

we selected the interlinked numbers as the scores for corresponding variables and got a Dachaihu Decoction syndrome diagnostic scale with the total score of 13. 5. ROC analysis showed that the area under the curve（ AUC） was 0. 916. Conclusion Alternate attacks of chills and fever

fullness and discomfort in chest and hypochondrium achieved the highest score in Dachaihu Decoction syndrome diagnostic scale

which was consistent with the traditional understanding of Dachaihu Decoction. It suggests that it is feasible to establish syndrome diagnostic criteria with Logistic regression analysis and ROC curve analysis.