The application of migrating corrosion inhibitors (MCI) is one of many methods of protecting reinforced steel in concrete structures,but the migrating ability is limited for dense concrete.The inhibition behavior of 3 kinds of migrating organic corrosion inhibitor (MCI) was investigated for reinforced steel rebar in simulated concrete solutions with Cl- through polarization curve and polarization resistance measurements.The permeability of BE in concrete specimen and its effect of inhibiting rebar corrosion were also investigated.The results show that BE is a mixed inhibitor,with inhibiting anodic and cathodic process of rebar simultaneously,and has better inhibiting effect for rebar than two marketable MCI’s from abroad.Electric field can accelerate BE to permeate into concrete,and thus it has better inhibiting effect for rebar.