ABSTRACT In this study, we optimized the baicalin water extraction process from Scutellaria baicalensis Georgi, Lamiaceae (a traditional Chinese medicine). Orthogonal test design L9(3)4 was used to analyze the optimization of water extraction process of baicalin from S. baicalensis. The effect of solid–liquid ratio, extraction time and soaking time on the yield of baicalin were investigated and optimized by orthogonal test. High-performance liquid chromatography was employed for the determination of extraction yield of baicalin. Analysis of variance was carried out to study the effects of the above three factors. The results showed that solid–liquid ratio plays a significant role in attaining maximum extraction yields of baicalin. However, the other two factors had some effect (not statistically significant) on the extraction yield of baicalin. Conclusively, the optimum experimental conditions such as the solid–liquid ratio (1:12), extraction time (30 min) and soaking time (1 h) for the water extraction of baicalin were proposed which can provide the maximum extraction yield of baicalin. In addition, the score based on the content of baicalin and total solid residues yield were used as evaluation indexes for baicalin uterus suppositories evaluation.