Relative contact angle and heat of wetting can be used to provide a measurement of surface wettability of synthetic magnetite. The comparison between synthetic and natural magnetite in terms of surface wettability showed that, using the same kind of wetting liquid, the difference in the relative contact angle was 10° between the concentrate and tailings obtained from reverse fl otation of synthetic magnetite, while the difference was more than 20° between the concentrate and tailings obtained from reverse fl otation of natural magnetite. As for the concentrate and tailings from reverse fl otation of synthetic magnetite with water as wetting liquid, the relative ratio of their wetting heat was 106.21%. In comparison, the relative ratio of wetting heat was 176.59% for concentrate and tailings from reverse fl otation of natural magnetite, showing a 70.38% difference.