Objective: To investigate the effect of Interleukin-6 on invasion and migration of the human HepG2 cells. Method: The HepG2 cells were treated by human IL-6, and Transwell chamber assay and wound scratch assay were used to test the cell invasion and migration respectively; the expression of STAT3, p-STAT3, RhoA and ROCK kinase proteins were detected by Western blotting; tumor was formed subcutaneously in nude mice and the tumor-bearing mice were treated by human recombinant IL-6, to observe the survival time and the changes in tumor volume in the nude mice. Results: At a concentration of 25 ng/ml for IL-6, proliferation or migration of the HepG2 cells were significantly enhanced; human recombinant IL-6 could promote the invasion and migration of the HepG2 cells; after the cells were treated by human recombinant IL-6, the levels of p-STAT3, RhoA and ROCK kinase proteins were significantly increased, the tumor growth in tumor-bearing mice was significantly increased and the survival time was significantly shortened. Conclusion: IL-6 can activate STAT3 to increase the expression levels of RhoA and ROCK, promote cytoskeletal remodeling, and thus promote invasion and migration of the HepG2 cells.