Abstract: Objective To investigate the expression of macrophage migration inhibitory factor(MIF) in human cervical cancer cells SiHa transfected MIF recombinant plasmid and its influence on CyclinD1 expression. Methods Recombinant eukaryotic expression plasmid pEGFP-N1-MIF was constructed and identifi ed, then transfected into human cervical cancer cells SiHa using a liposome approach. The expression of MIF in supernatant fluid was detected by ELISA. The changes of MIF, CyclinD1 mRNA and protein expression were detected by real-time PCR and immunocytochemistry respectively. MTT assay and Boyden small chamber were performed to examine the changes of cell proliferation and migration in vitro respectively. Results The recombinant plasmid pEGFP-N1-MIF was constructed successfully and transfected into SiHa cells. The expression level of MIF in supernatant fl uid of the experimental group was higher than that in negative control group and blank control group (P<0.01). After transfection, the MIF, CyclinD1 mRNA and protein expression level in experimental group were significantly higher than that in negative control group and blank control group (P<0.01). In comparison with negative control group and blank control group, the proliferation and migration ability in vitro of experimental group was significantly higher(P<0.01). Conclusion MIF expression level in SiHa cells is increased after recombinant plasmid transfection. The over-expression of MIF gene can signifi cantly promote proliferation and migration ability of SiHa cells in vitro, and up-regulate the expression of CyclinD1.