Objective:To prove the effect of PADI-4 gene in the development of rheumatoid arthritis.Methods:Four SiRNA sequences were designed for PADI-4 gene,and the SiRNAs were cloned into blank pSiRNA-hH1neo G2 vectors.The vectors were transformed into GT116 E.coli competent cells.By white-blue selection system,the right vectors were gotten.After transfection into HL-60 cells,the cells were collected on 3,5,7,10 and 14 day,the levels of PADI-4 mRNA were detected by Real-time PCR.Results:Digestion by Acc 65Ⅰand Hind Ⅲ,the recombinant expressive vector of RNA interference was obtained successfully.The PADI-4 mRNA generated by the cells transfected with the vector of SiRNAs were reduced,and the level was not change in normal cells.Conclusion:The recombinant expressive vector of RNA interference is obtained successfully and the recombinant expressive vector can affect expression of PADI-4 gene in HL-60 cells.