Objective: To investigate the role of Hes1 in migration, invasion and epithelial-mesenchymal transition in cervical cancer cells. Methods: Real time quantitative PCR(RT-qPCR) and Western blotting were used to detect the expression of Hes1 in four cervical cancer cell lines. Hesl knockdown was performed by siRNA. The effects of down-regulation of Hes1 on migration and invasion in cervical cancer cells were evaluated by transwell assays. The main factors of epithelial-mesenchymal transition effected by Hesl knock down were measured by RT-qPCR and Western blotting. Results: The expressions of Hesl mRNA in four cervical cancer cell lines showed statistic differences (χα=10.39, P=0.016). Knockdown of Hes1 led to statistic differences in the numbers of cell passing through the chamber, between SiHa NC group and SiHa 1 group, HeLa NC group and HeLa 1 group (P<0.05, both) in both migration assays and invasion assays. After Hes1 RNA interference, compared to blank and negative control, the expression of E-cadherin was significantly reduced in SiHa and HeLa (both P<0.05), while ZEB1, Slug were induced in SiHa (both P<0.05), and vimentin, Slug were induced in HeLa (both P<0.05). Conclusions: Hes1 may have a role in suppressing migration and invasion in SiHa, HeLa cells, and subsequent down-regulation induces the epithelial-mesenchymal transition, thereby suggesting a possible role in migration and invasion of cervical cancer cells mediated by epithelial-mesenchymal transition. [ABSTRACT FROM AUTHOR]