Abstract: Objective 　To study the effect of hypoxia-inducible factor-1alpha ( HIF-1α) on hepatic cancer cell line Hep G₂ growth in vivo and its mechanisms. Methods 　Hep cells (1 (10⁶ / mouse) were inoculated subcutaneously into 20 nude mice. The weights of subcutaneous tumor were detected. The resected specimens were made into paraffin-embedded sections. The expressions of HIF-1α and vascular endothelial growth factor (VEGF) proteins were analyzed by Western blot and Immohistochemistry ( ISH) . Results 　The growth rates of HIF-1α treating hepatic cancer cells Hep G₂ were significantly increased. Conclusion 　 The HIF-1α could promote hepatic cancer cell line Hep G₂ growth in vivo and it s mechanism may be due to the fact that it can promote vascular growth.