An E1-deleted adenoviral vector, pAdl2/RSV-IFN-bpA, harboring human IFN-gamma cDNA, and plasmid pJM17 were cotransfected into a human embryo kidney cell line 293 by the calcium-phosphate precipitation method. Six strains of recombinant adenovirus (rAd) were obtained after 11-day incubation. PCR analysis indicated that all six rAds contained human IFN-gamma cDNA. The biological activity of IFN-gamma was detected in the supernatant of the cultured 293 cells following rAd infection, and it could be blocked by the antibody against IFN-gamma. The B16F10 cells infected with the purified rAd (RSV/IFN-01) didn't show cytopathic effect (CPE), and more biological activity of IFN-gamma was detected in the supernatant of the infected B16F10 cells with increased MOI (multiple of infection) values. Therefore, the recombinant adenovirus constructed in this study can express and secrete human IFN-gamma.