Abstract: The resisting ability of gunning material for blast furnace to CO corrosion was invesitigated under the pure CO and the mixed gas condition through adding hydrogen into pure CO. A standard for testing the resisting ability of refractory to corrosion with mixed gas instead of pure CO has also been discussed. The results showed that the addition of hydrogen acclerates the CO corrosion on gunning material and the corrosion degree of refractory with the pure CO,200 h is same as that with the 95%CO + 5%H₂, 24 h. So, It is reasonable to use 95%CO + 5%H₂, 24 h instead of pure CO, 200 h to test the resisting ability of refractory to CO corrosion.