Objective To establish a kind of gene therapy method of rheumatoid arthritis, to construct the interleukin-18-PE38 fusion gene expression vectorand to explore the expression of the fusion gene in the chondrocytes and 3T3 cells. Methods Interleukin-18-PE38 fusion gene was cleaved from plasmid PRKL459k-IL-18-PE38 by restriction enzyme digestion,then linked with vectors PsecTag2B and transformed into competence bacteria, positive clones were selected and confimed by restrictive enzyme(EcoRI) digestion assay. The rearrangement plasmid PsecTag2B-IL-18-PE38 was transfected into 3T3 cells and mouse chondrocytes by liposome protocol(experimental group),null vector was used as negative control, and the transient expression was identified by fluorescence immunocytochemical assay. Results Restrictive enzymes digestion analysis revealed thatthe length of theinterleukin-18-PE38 fusion gene was 6 000 bp. Fluorescence immunocytochemical method showed that fluorescence intensity of the experimental group is b,whilefluorescence intensity of the control group is weak. Conclusion the eukaryoticexpression vector PsecTag2B-IL-18-PE38 is established successfully which canbeexpressed in the 3T3 cells and mouse chodrocytes. Our results lay a foundationfor the further investigation for rheumatoid arthritis therapy.