This kit employs solid phase, indirect ELISA method for detection of IgG antibodies to HAV (anti-HAV) in serum or plasma with two-step incubation procedure. Polystyrene micro well are pre-coated with purified natural HAV antigen. The HRP conjugated mouse anti human IgG (r chain) monoclonal antibody serves as tracer. TMB is substrate for HRP. The enzyme reaction with substrate TMB produces a color change, and the intensity of the absorbance at 450 nm indicates the presence or absence of Anti-HAV antibodies IgG in the sample. The test is specific, sensitive, reproducible and easy to operate. It is for blood screen of HAV infection.