Abstract: The surface morphology, thickness and microstructure of oxide scale of rebar were observed by optical microscope and electron backscatter diffraction. The effect of surface oxide scale on corrosion resistance of rebar under different cooling bed temperatures were discussed. The results show that with the increase of cooling bed temperature, the surface morphology of oxide scale of rebar tends to be smooth, the thickness of oxide scale increases, the compactness increases. The oxide scale is mainly composed of Fe₃O₄ and FeO, but the content and distribution are different with diverse cooling bed temperatures. With the increase of the cooling bed temperature, the corrosion resistance of bar is enhanced.