To establish a highly sensitive time-resolved immunofluorometric assay of human interferon-gamma. A two-site “Sandwich”-type time-resolved immunoflourometric assay for human interferon-gamma is described. It is based on usage of specific polyclonal and monoclonal antibodies. The polyclonal antibody to bind the interferon-gamma in samples are immoblailized on the surface of microtiter plate strip wells.Following capture of IFN-γ present in sample. Then monoclonal antibody, which is biotinylated,is added to wells.The second biotin labeled antibody will allow the subsequent specific binding of Eu³⁺ labeled streptavidin. After the immunoreactions completed, the bound fraction of Eu³⁺-label is quantified by dissociating it in a fluorescence-enhancement solution and measuring its fluorescence with Wallac 1234 fluorometer. The sensitivity of the assay is 0.02 μg/L. The standard curve is linear from 0.02 μg/L to 400 μg/L. The time-resolved immunofluorometric IFN-γ assay is quick, sensitive and suitable for testing large numbers of samples, and may be useful in both industrial producing and clinical studies.