A new micronanometer coating on regenerator of hot blast stove for energy saving was prepared by ultra fining technology. The results showed that the emissivity of coatings is 0.93 and its thickness is about 300 μm. Application of hot stoves with such regenerators to 350 m3 and 1750 m3 BF indicated that the coating makes the blast temperature increase by 57 ℃ and 28 ℃ respectively, reduces the fluctuation of blast temperature, leads to a fuel saving of 10% due to intensification of heat radiation convection,and increasing heat conductivity of bricks resulting in increase of heat capacity of the regenerator, It can be seen that application of such coating gives good economic benefits.