Objective To investigate the G2 cell cycle arrest and apoptosis induced by HIV-1 Vpr gene on Hela,Lovo and HepG2 cancer cells.Methods Recombinant vector pcDNA4-Vpr was constructed by DNA recombination technology and was then transfected into Hela,Lovo and HepG2 cells.Meanwhile,pcDNA4-EGFP plasmid group,FUGENE group and blank group were also set up as control.Ratio of cytostasis was evaluated by MTS assay 24 h,48 h and 72 h later,cell cycle arrest examined by flow cytometry and apoptosis detected by staining with ANNEXIN V and PI double dyes.Results Compared to the control group,the value of inhibition ratio,G2 arrest and apoptosis of Hela,Lovo and HepG2 cells increased obviously 24 h,48 h and 72 h after the transfection ( P ＜ 0.05 ).72 h after the transfection,the inhibition ratio of Hela,Lovo and HepG2 was 29.67％,27.35％ and 31.67％ respectively.Percentage of G2 phase cells was 24.9％,18.8％and 32.1％ respectively.Apoptosis percentage of Hela,Lovo and HepG2 ceils was 15.46％,7.7％ and 41.5％ correspondingly.Conclusion HIV-1 Vpr gene can induce cell cycle G2 arrest and apoptosis of Hela,Lovo and HepG2 cell lines in vitro.