In this work, the corrosion behavior of the surface parallel to the oriented c-axis (c∥) and perpendicular to c-axis (c⊥) in the (Ce0.15Nd0.85)30FebalB dual main phase magnet was studied. With the addition of Ce, the volume fraction of RE-rich phase shown in the backscattered electron (BSE) images is basically approximate on the two surfaces. The free corrosion potential (Ecorr) of the c∥ surface is more negative, which shows the worse corrosion resistance from the perspective of thermodynamics. While the reaction kinetics parameters with the smaller free corrosion current (icorr) and the larger transfer resistance (Rct) react the opposite conclusion in 3.5 wt% NaCl solution. Moreover, the c∥ surface performs smaller ions concentration of corrosion product and less damaged corrosion morphology compared to c⊥ surface after the free corrosion. The inconformity is not affected by the RE-rich phase, but by the anisotropy of the grains that the c∥ surface has larger density of the atoms and the lower ratio of (Nd, Ce)/Fe.