Abstract: We established a quality evaluation method for Shuanghuanglian preparations based on an effect-constituent index (ECI), which is guided by the clinical efficacy of Shuanghuanglian and a dose-efficacy correlation. An HPLC method was used to establish the quantitative fingerprint of Shuanghuanglian from different manufacturers and to determine the content of 10 fingerprint components, including baicalin, chlorogenic acid, forsythin, galuteolin, wogonin, forsythoside A, luteolin, caffeic acid, baicalein, and scutellarin. Using Staphylococcus aureus as biological model, the potency of Shuanghuanglian preparations was determined by antibiotic microbial assay. Using the method of PLC-DA, the efficacious antibacterial components were screened by "dose-efficacy" correlation analysis. According to the antibacterial potency and content of the antibacterial ingredients, combined with the method of the custom weight coefficient, ECI was calculated and verified. The results show that the antibacterial ECI can facilitate evaluation of the efficacy of Shuanghuanglian based on the composition of its contents, providing a new method for the quality control of traditional Chinese medicine.