Abstract: Objective To investigate the changes in the invasiveness of cervical cancer cell line CaSKi and the expression of vascular endothelial growth factor (VEGF) in response to treatment with anti-HPV16 E6-ribozyme, which plays a important role in the malignant phenotype and conversion of cervical cancer cells. Methods By means of lipofectin transfection, anti- HPV16 E6-ribozyme and empty eukaryotic expression plasmids were respectively transfected into CaSKi cell line (designated as CaSKi-R and CaSKi-P respectively). CaSKi, CaSKi-R and CaSKi-P cells were observed for their cell growth curves, clone forming ability on soft agar and tumorigenicity in nude mice. One-step reverse transcriptional PCR (RT-PCR) was employed to examine the expression of VEGF. Results No significant differences were found in the growth rate, clone forming ability and tumorigenicity between CaSKi and CaSKi-P cells. In contrast, CaSKi-R exhibited obviously decreased growth rate, clone forming ability and tumorigenicity (P<0.05). RT-PCR analysis showed that the expression levels of VEGF mRNA in CaSKi-R cells were lower than those in CaSKi-P and CaSKi cells. Conclusion Anti-HPV16 E6-ribozyme may reduce the proliferative ability and invasiveness of cervical cancer cell line CaSKi, possibly through decreasing VEGF expression in CaSKi cells.