An experimental study has been carried out to investigate the effect of microstructure on sliding wear behavior of Fe-Al coatings and Fe-Al/WC composite coatings produced by high velocity arc spraying (HVAS) and cored wires. After heat treatment at 300℃, 450℃, 550℃, 650℃ and 800℃, the microstructure of the coatings will be changed. The changes of microstructure have obvious effects on the microhardness of the coatings, which may be the most important factor influencing the coatings sliding wear behavior. After heat treated at 450℃-650℃, increasing of the amounts of iron aluminides (including Fe3Al and FeAl ) and dispersion strengthening of Fe2W2C and Fe6W6C will lead to a rise of microhardness of the coatings. Increasing the microhardness through heat treatment would improve the sliding wear resistance of the iron aluminide based coatings coatings.