Abstract: Objective To investigate inhibitory effect of Baohuoside-Ⅰ from Cortex Periplocae on esophageal carcinoma in vivo and in vitro and to study its probable mechanisms. Methods Stepwise analysis method including chromatograph and HPLC was used for the preliminary isolation and purify of Baohuoside-Ⅰ.The components were identified by Thin Layer chromatogram and ESI-MS. The growth inhibitory effect of Baohuoside-Ⅰ on Eca109 cell line was examined by MTT assay, the change of cell cycle and the induction of apoptosis were analyzed using flow cytometry. Eca109 cells were injected into subcutaneous tissue of nude mice to establish tumor model. Baohuoside-Ⅰ was used to treat model mice by intramuscular injection. Compared with control group, the growth curves of tumor was drawed and the growth inhibition rates of tumor was calculated. Results Baohuoside-Ⅰ could significantly inhibit the proliferation of Eca109 cells, the effect was in dose-dependent manner, Baohuoside-Ⅰ could arrest the cell cycle at G0/G1 phase and induce apoptosis of Eca109 cells in a time-dependent manner. The apoptotic rate reached （49.2±2.12）% after treatment with 50μg/ml Baohuoside-Ⅰ for 48 h. The model of esophageal carcinoma in nude mice was successfully established. The growth of tumor treat by Baohuoside-Ⅰ was obviously suppressed compared with control group (P<0.01). The growth inhibition ratio of tumor reached （60.9±0.16）%. Conclusion Cell growth in vitro and in vivo was significantly inhibited by Baohuoside-Ⅰ and it might exert its anti-tumor activity by blocking the cell cycle and inducing apoptosis of tumor cells.