OBJECTIVE：To provide reference for deepening the scientific connotation of “tocolysis” efficacy of Scutellaria baica- lensis. METHODS： The ancient and modern “tocolysis” efficacy of S. baicalensis were compared in respects of historical evolution， ancient TCM theory and modern pharmacology； the reasons for the ancient and modern difference were inferred and analyzed. RESULTS： The “tocolysis” efficacy of S. baicalensis was recorded in many ancient herbal works. The “tocolysis” efficacy of S. baicalensis was associated with bitter taste and cold nature， but differentiation of symptoms and signs should be based on the basic theory of TCM. At the same time， The “tocolysis” efficacy of S. baicalensis was also accoiated with the effects of clearing heat and anti-inflammatory， inhibiting viral replication， enhancing immunity and inhibiting uterine contraction. The difference of ancient and modern “tocolysis” efficacy of S. baicalensis had a great relationship with changes in genuineness， the difference in understanding of the concept of ancient and modern “tocolysis” and changes in clinical application. CONCLUSIONS： It provides reference for further study and clinical application of S. baicalensis to understand the difference of ancient and modern “tocolysis” efficacy.