New Bunyavirus is a brand-new virus, whose genome is composed of three single negative strand RNA fragments, L, M and S. Now it belongs to the third group of virus of the genus Phlebotomycovirus of Bunyaviridae, and has the highest homology with Ukunimi virus of the genus Phlebotomycovirus (38.83% of nucleic acid homology and 28.57% of amino acid homology)[1]。 Neobuniavirus has been proved to be an important pathogen of fever with thrombocytopenia syndrome (SFTS), and the disease caused by this virus has a high mortality rate[2]。 There are outbreaks in Hubei, Anhui, Henan, Shandong, Jiangsu, Zhejiang and other provinces in China, which have received wide attention. With the attention of local governments to the prevention and control of SFTS, the demand for new bunia virus antibody detection kits is increasing. However, there are few manufacturers producing ELISA kits in China, which seriously affects the progress of new bunia virus antibody detection. Using the isolated strains of new bunia virus and the established methods for quantitative detection of new bunia virus nucleic acid, we established an indirect immunofluorescence assay (IFA) method for detection of IgG antibodies of new bunia virus, which can be used for the diagnosis of SFTS cases, the investigation of population immune level, and the detection of virus antigens in animal tissues, etc., and provide experimental basis for diagnosis and treatment and epidemiological prevention and control.