Esophageal cancer is one of the most common malignancies and is associated with a dismal prognosis. Although treatment options have increased for some patients, overall progress has been modest. Thus, there is a great need to develop new treatments. We found that Baohuoside-I, a flavonoid extracted from a Chinese medicinal plant, exhibits anticancer activity. Here, we demonstrated that Baohuoside-I significantly inhibited Eca109 human esophageal squamous carcinoma cell proliferation and induced Eca109 cell apoptosis in vitro and in vivo. The growth inhibitory effect of Baohuoside-I on the Eca109 tumor cell line was examined by MTT assay; the induction of apoptosis was analyzed by flow cytometry. Eca109-luc cells were injected into the subcutaneous tissue of nude mice to establish xenograft tumors. Our results revealed that Baohuoside-I caused a dose- and time-dependent inhibition of cell growth and an induction of apoptosis. Furthermore, Baohuoside-I-treated cells were characterized by decreased expression of the β-catenin gene and protein in the total cell lysates. Thus, the gene and protein expression of the downstream elements survivin and cyclin D1 was downregulated. To determine the precise inhibitory mechanisms involved, further in-depth in vivo studies of Baohuoside-I are warranted. Our study provides the first evidence that Baohuoside-I inhibits tumor growth and induces apoptosis by inhibiting β-catenin-dependent signaling pathways. Thus, Baohuoside-I is a potential candidate in ESCC disease therapy.