Scutellaria baicalensis Georgi. is a widely used clinical TCM, distributing in HeBei、ShanDong、LiaoNing et al. The content of baicalin is difference for their producing area are differentia. However, quality control of baicalin products is often not performed due to lack of standardization, resulting in inconsistent efficacies and sometimes serious toxicity. The goals of this study were to determine the best extraction of baicalin and to establish a method to measure authenticity, chemical consist...