This kit detects hepatitis D virus IgM antibody (HDV-IgM) in human serum or plasma samples, polystyrene microwell strips are pre-coated with antibodies directed to human immunoglobulin M proteins (anti-μ chain). After first adding serum or plasma specimens to be examined, the IgM antibodies in the specimen can be captured, and other unbound components (including specific IgG antibodies) will be removed by washing. In the second step, the HRP (horseradish peroxidase)-conjugated antigens will specifically react only with HDV IgM antibodies. After washing to remove the unbound HRP-conjugate, chromogen solutions are added into the wells. In presence of (anti-μ) - (HDV-IgM) - (HDV Ag-HRP) immunocomplex, after washing the plate, the TMB substrate was added for color development, and the HRP connected to the complex catalyzes the color developer reaction to generate the blue substance, add 50μl of Stop Solution, and turn yellow. The presence of the absorbance of the HDV-IgM antibody in the sample was determined by a microplate reader.