Abstract: The effect of rare earth element Ce on the microstructure of hot dip aluminum(HDA) coating on Q235 steel have been studied by means of SEM and XRD.The anticorrosive property and oxidation resistance of the coating was also studied by immersion test in 3.5% sodium chloride solution and at 900 ℃ for 300 h respectively.If the content of Ce in the hot dip aluminum bath was lowere than 0.3%,with increasing the content of Ce in the bath,the anticorrosive property and oxidation resistance of HDA coating were improved obviously.If the content of Ce in the bath was higher than 0.3%,the properties of the HDA coating became poor.By adding Ce into the HDA bath,the saw-toothed shape of transition layer of HAD coating became smooth,FeAl3 phase distributed in the surface layer in netted shape,but the thickness of the transition layer varied little with increasing the content of Ce in the bath.If the content of Ce was more than 0.3% in the bath,the Ce compound separated out in strip-like shape in the surface layer and got together in the boundary of FeAl3 phase,and with increasing the Ce content in the bath,the shape of Ce compound became blocky and the degree of segregation was more serious.