Objective:To investigate the expression of the recombinant plasmid of HIV-1 viral protein regulatory(Vpr) in the eukaryotic cells, and evaluate the effect on Kaposi’s sarcoma-associated herpesvirus(KSHV) lytic cycle replication by Vpr protein in BCBL-1 cells. Methods:After identification with enzyme digestion and nucleotide sequences analysis,the recombinant plasmid pVpr-Flag was transiently transfected into BCBL-1 cells and NIH3T3 cells. The mRNA and protein expression of pVpr-Flag in both cells was detected by RT-PCR, IFA and Western blot,respectively. Subsequently, RNA was obtained from BCBL-1 cells transfected with pVpr-Flag plasmid. RT-PCR was carried out to evaluate the expression of ORF26 mRNA(encoding the minor capsid protein) of KSHV. Results:Nucleotide sequences analysis indicated that the cloned Vpr sequence was 100% homology with Vpr gene registered in GenBank previously. The specific band was detected at the expected place both by RT-PCR and Western blot. And the expression of Vpr protein was also detected in BCBL-1 cells by IFA. In addition,the expression of ORF26 mRNA in BCBL-1 cells transfected with plasmid pVpr-Flag was weaker than that in the control. Conclusion:Vpr gene was correctly expressed in BCBL-1 and NIH3T3 cells,and Vpr protein might inhibit KSHV lytic cycle replication