The microstructures and corrosion behavior of 1.0wt% Gd-containing neutron-absorbing duplex stainless steel annealed at different temperatures were studied. Results reveal that the content of Gd-containing secondary phase increases with increasing the annealing temperatures to 1080 ℃, and then decreases. In the sample annealed at 1080 ℃, M-Gd (M=Fe, Cr, Ni) intermetallic with M₃Gd as the core phase and M₁₂Gd as the shell is the primary secondary phase. In the sample annealed at 1140 ℃, M₃Gd phase is dominant. The corrosion behavior of the two annealed steel samples were analyzed in NaCl, HCl and H₃BO₃ solutions. It is found that the sample annealed at 1140 ℃ has lower corrosion rate. M₃Gd is more electrochemically active than M₁₂Gd when the sample is immersed in NaCl and HCl solutions, but more noble in H₃BO₃ solution.