Osteopontin (OPN) is able to enhance migration of tumor cells through activation of metastasis-related genes involving many signal pathways. Calpain small subunit 1 (Capn4) plays important roles in tumor metastasis. The mechanism of migration of hepatoma cells mediated by OPN was investigated by reporter gene assay, RT-PCR, Western blot analysis and wound healing assay. It was found that OPN was able to upregulate the expression of Capn4 at the levels of promoter activity, mRNA and protein in human hepatoma HepG2 cells. The treatment with PDTC (an inhibitor of NF-κB) could abolish the upregulation of Capn4 mediated by OPN. Moreover, wound healing assay showed that OPN was able to promote the migration ability of hepatoma cells through upregulating Capn4. Thus, It was concluded that OPN is able to upregulate Capn4 through NF-κB in promotion of migration of hepatoma cells.