For investigating the long-term corrosion resistance of stainless steel rebar in coral concrete， the corrosion current densities of stainless steel rebar type 304 and 2205 were measured by applying the linear polarization resistance， electrochemical impedance spectroscopy， and polarization curve methods in the coral concrete in 3.5% NaCl solution for 750 days. Simultaneously， the corrosion current density was compared to that of the carbon steel in the similar strength grade of ordinary concrete. The results suggest that the corrosion current density of the stainless steel rebar is lower than 0.10 μA/cm²， and maintained passivation in the coral concrete after 750 days in 3.5% NaCl solution. In comparison， the corrosion current density of stainless steel rebar type 2205 is lower than that of the 304 counterparts. Moreover， the corrosion current density of the carbon steel rebar is 10 times higher than that of the stainless steel rebar with the result that the former samples are severely corroded. In general， the corrosion state calculated from the linear polarization resistance is most consistent with the observed. Therefore， the linear polarization resistance method is proposed to test the corrosion rate of rebar in concrete.