Abstract: Two pulverized coals with different slagging tendencies were combusted in a pulverized coal boiler in which three kinds of refractory plates were arranged uniformly. After combustion, the slagging behavior of coal ash on the refractory plates was observed. In order to examine the degree of corrosion by fly ash, the cross-sectional of refractory plates were investigated by energy spectrum analysis. The results show that with the rise of temperature in the furnace, the slagging degree on the surface of refractory plates and the corrosion degree increase. When the temperature in the furnace is higher than the melting temperature of fly ash, the slagging degree on the surface of refractory plates increases sharply. In industrial boilers, the surface temperature of refractory plates lower than the fly ash melting temperature can effectively reduce the possibility of surface slagging. In addition, compared with the jade texture refractory plates, the silicon carbide refractory plate has superior anti-slagging properties.