Stress corrosion cracking behaviors of RS/PM Al-9Zn-2.5Mg-1Cu alloys with the addition of 2%Fe, 2%Mn, and 1%Fe+1%Ni, respectively, were examined in the present study. Each alloy was exposed to 3.5% NaCl aqueous solution under an applied stress of 200MPa for 5 and 20 days, respectively, and tensile tested in air. The alloys containing Fe+Ni and Mn showed a significant reduction in ductility after exposure for 20 days. SEM fractographic studies indicated that the size and depth of dimples, as well as the sign of plastic deformation around dimples, were greatly reduced after exposure for those alloys susceptible to stress corrosion cracking. The present study strongly suggested that hydrogen played an important role in stress corrosion cracking behaviors of Al-9Zn-2.5Mg-1Cu alloys with the addition of 2%Mn and 1%Fe+1%Ni, respectively.