Objective To study the effect of Qige San ethyl acetate extract on the proliferation of human esophageal carcinoma Eca109 cells and to explore its possible mechanism. Methods Inhibitory effects of Qige San ethyl acetate extract on the proliferation of esophageal carcinoma Eca109 cells were detected by MTT assay, cell apoptosis was detected by flow cytometer, and the expression of protein STAT3, Bcl-2 and Caspase 9 was detected by Western blotting method. Results In the range of 10~100 μg/mL, Qige San ethyl acetate extract inhibited the proliferation of Eca109 cells effectively (P<0.05) . Compared with the control group, Qige San ethyl acetate extract in the concentrations of 1.47, 33.26, 75.52 μg/mL significantly increased the apoptotic rate of Eca109 cells within 48h ( P<0.01). And Western blotting results showed that the ex pression levels of STAT3 and Bcl-2 were reduced, and Caspase 9 was increased with the increase of drug concentration. Conclusion Qige San ethyl acetate extract could significantly inhibit the proliferation of Eca109 cells and induce cell apoptosis, and its mechanism is probably associated with the inhibition of signal transducers and activators of transcription 3 (STAT3) signaling pathway.