Since chicken and egg products are widely exported and imported, there is a distinct possibility that Avian Influenza Virus (AIV) may be transmitted and cause epidemics among poultry. There is the additional fear that AIV may become infective to humans. From the point of food safety and risk, we attempted to determine AIV survivability in egg products. We investigated the inactivation of AIV in mayonnaise, which is a typical and widely consumed egg product. A model mayonnaise was made of salad oil, vinegar, egg yolk and salt, similar to commercial products. The following isolates of AIV virus were used in this experiment: A / whistling swan/Shimane/499/83 (H5N3) (H5 AIV), A/whistling swan/Shimane/42/80 (H7N7) (H7 AIV) and A/duck/Hokkaido/26/99 (H9N2) (H9 AIV). After the model mayonnaise and AIV were mixed, H7 AIV and H9 AIV were inactivated immediately, and their infectivity titers decreased to under the detection limit . In the case of H5 AIV, the infectivity titer decreased from 105.0EID50/0.1 ml to under the detection limit after 30 min. These results demonstrated that different isolates of AIV were inactivated in mayonnaise. The inactivation of AIV may be caused by the chemical properties of mayonnaise, such as salt concentration, acid concentration and /or pH.