Abstract: In this study, we investigated the effect of aspirin on tumor biological effects mediated by hepatocyte growth factor/cellular-mesenchymal-epithelial transition factor (HGF/c-Met) axis, and preliminarily explored the molecular mechanism of inhibiting tumor metastasis by aspirin. The binding of aspirin to c-Met was predicted by molecular docking; cellular thermal shift assay (CETSA) was used to verify the binding of aspirin to c-Met at the cellular level. The inhibitory effect of aspirin on c-Met kinase was detected by kinase activity; Western blot, cell scattering test, cell branching morphogenesis and Transwell test were used to evaluate the cell signal transduction, morphological changes and migration and invasion ability. The results showed that aspirin could effectively inhibit the kinase activity of c-Met with a half inhibitory concentration of 0.95 mmol·L^-1. The results of docking showed that aspirin could bind to the ATP pocket of c-Met protein, and the main binding sites were Tyr1230, Tyr1159 and Met1229. The CETSA test also showed that aspirin could form binding complex with c-Met protein. Western blot results showed that aspirin could inhibit the up-regulation of phosphorylated Met stimulated by HGF in a concentration-dependent manner. The results of cell scattering test showed that aspirin could block HGF/c-Met promoted cell scattering in a concentration dependent manner. Aspirin could almost completely block the biological function mediated by c-Met activation at the concentration of 4 mmol·L^-1, and this effect was independent of HGF. Similarly, the results of MDCK cell branching morphogenesis experiment showed that aspirin could inhibit HGF/c-Met mediated invasive growth in a concentration dependent manner. The results of Transwell test showed that aspirin could block HGF/c-Met mediated cell migration and invasion in a concentration-dependent manner. Aspirin could almost completely block the biological function mediated by c-Met activation at the concentration of 4 mmol·L^-1, and this effect was independent of HGF. The above results indicate that aspirin can bind to c-Met, thereby blocking the biological effects mediated by HGF/c-Met, and inhibiting tumor metastasis. This study revealed the new biological function of aspirin, and provided a new theoretical basis for a comprehensive understanding of the anti-metastatic effect of aspirin.