In the present study, the effect of simulated firing cycle on age-hardenability of Au-Cu-Zn alloy containing Cr at intraoral temperature was evaluated by means of hardness test, X-ray diffraction (XRD) study, scanning electron microscopic (SEM) observation, electron probe micro analysis (EPMA) and differential thermal analysis (DTA) after solution-treatment and then aging at intraoral temperature after simulated firing cycle. The Au-Cu-Zn alloy containing 10-15 at.% Cr was softened during simulated firing, and was hardened during cooling process after simulated firing. The hardening effect during cooling process of the Au-Cu-Zn alloy containing 10-15 at.% Cr after simulated firing cycle decreased apparently by the repetitive firing. The Cr addition up to 15 at.% instead of Cu in AuCu-20Zn (at.%) alloy did not result in appreciable change of the order-disorder transition temperature and solidus temperature. The age-hardenability at intraoral temperature of Au-Cu-Zn alloy containing 10-15 at.% Cr decreased apparently after solution-treatment and then simulated firing and aging at intraoral temperature.