Abstract: Objective To establish immunological methods specific for detecting antigens in different groups of monoclonal antibodies.Methods Indirect immnofluorescence assay was applied to identify specificity of the two groups of monoclonal antibodies prepared with crude antigen and recombinant antigen of Aspergillus fumigatus,respectively.Two different double monoclonal antibody sandwich EL ISA assays established with the two groups of antibodies were performed to detect antigents in the cell culture supermatants of 19 common species of Aspergillus,Penicillium marneffei,and 5 species of Candidas.Results The results of indirect immnofluorescence assay indicated that the monoclonal antibodies prepared with crude antigen of Aspergillus fumigatus were specific for antigens in both clinical isolates and environmental isolates of Aspergillus,whereas the other group of monoclonal antibodies was proved to be specific for Aspergillus fumigatus of both clinical and environmental isolates.The ELISA assay established with the crude antigen-specfic monoclonal antibodies could detect both of the clinical and environmental isolates of Aspergllius,while the other assay could only detect Aspergillus fumigatus of both clinical and environmental isolates.And no cross reaction with the cell culture of Penialllium marneffei and Candidas was observed with the two methods.Conclusion The EL ISA assays can detect both of the clinical and environmental isolates of Aspergillus,and differentiate Aspergillus fumigatus from other species of Aspergillus.The study provides us with new tools for monitoring the contaminmetion of Aspergillus in the environment,agricultural commodities and food,and this is also useful for early diagnosis of patients with aspergillosis.