Objective To test protective effect of inactivated HA vaccine on marmosets.Methods Inactivated HA vaccine was prepared by culturing the strain YN5 of HA virus in Vero cells. Its immunogenicity and protection was studied in marmosets(Saguinus). Results Specific anti-HAV antibodies were induced in 7 common marmosets, and no elevation of serum enzyme activity or pathological exchange of liver tissue were observed. The vaccine protected marmosets against the intravenous challenge with virulent HAV(Han-ZD). But the elevation of serum enzyme activity and pathological exchange of liver tissue were showed in all the control marmoets. Conclusion The inactivated HA vaccine (YN5) had good immunogenicity and protective effect.