Fe-Mn-C twinning-induced-plastic (TWIP) steel was prepared by adding Cr and Mo, and the effect of Cr/ Mo carbides on the corrosion behaviour of TWIP steel was studied. Different contents of carbide were obtained by aging treatment. The parameters for heat treatment method were 1150 ℃ and 2 h solid solution treatment, aging at temperature 700 °C, heat preservation for 6 and 24 h. Results show that the carbide precipitation phase occurred preferentially in the grain boundary and partly at the interior of grain when the aging time increased. The carbide precipitation phases were primarily MoC and Cr3C2. Cr/ Mo carbide and austenite matrices exhibited phase potential difference and formed a local galvanic couple. More carbides were precipitated, and more galvanic couples were generated as the aging time increased, which resulted in serious corrosion.