The effects of oxidation on flotation recovery of oxidation at 20 degrees C, 50 degrees C and 100 degrees C for periods up to 100 hours were investigated using an alcohol type frother. The recovery of the floated coal decreased from 95 percent to 24 percent after oxidation. As a result of measurements with a low-ash bituminous coal, flotation is suggested as a method of investigating the initial stages of oxidation of coal particles.