Objective To investigate the inhibitory effect of Boschniakia rossica boschnaloside (BRBN) on the epithelial-mesenchymal transition (EMT), invasion, and migration of human hepatoma SMMC-7721 cells. Methods Transforming growth factor β₁ (TGF-β₁) was used to induce an EMT model of SMMC-7721 cells. The cells were divided into a control group, model group, and BRBN group. Cell migration was detected with a wound healing test, and cell invasion was observed by Transwell chamber assay. The expression of E-cadherin, N-cadherin, Vimentin, Slug, Twist1, ZEB1, and signal transducers and activators of transcription 3 (STAT3) were determined with the Western blot method. Results TGF-β₁ resulted in spindle-shaped SMMC-7721 cells, down-regulated the expression of E-cadherin, and upregulated the expression of N-cadherin and vimentin, suggesting that SMMC-7721 cells obtained a mesenchymal phenotype. Compared with the model group, the BRBN group SMMC-7721 cells’ expression of E-cadherin was significantly increased, their expression of N-cadherin and vimentin were reduced, and their expression of Slug, Twist1, and ZEB1, as well as STAT3 phosphorylation, were down-regulated. Conclusions BRBN inhibits the invasion and migration of human hepatoma SMMC-7721 cells, possibly by reversing EMT through the STAT3 pathway.