Objective To investigate the effect of lysophosphatidic acid (LPA) on migration of hepatocellular carcinoma MHCC97H cells and its involved mechanisms. Methods Transwell was utilized to investigate the impact of LPA on cell migration of MHCC97H cells. Furthermore, the role of ROCK in the migration of MHCC97H cells through Y-27632 (a specific inhibitor of ROCK). Then, the expression of F-actin was observed with immunofluorescence staining and Western blotting. Atomic force microscopy (AFM) was employed to investigate elastic modulus of MHCC97H cells. Results LPA significantly promoted the migration of MHCC97H cells, while Y-27632 significantly blocked the migration of MHCC97H induced by LPA. Moreover, LPA up-regulated the expression of F-actin and decreased the elastic modulus of MHCC97H cells. Conclusions LPA promotes MHCC97H cell migration through decreasing the cell stiffness via ROCK/F-actin.