Froth properties and their relation to the concentrate grade play an important role in monitoring flotation running conditions and predicting flotation concentrate quality. In this paper, the correlation between the froth properties and clean coal ash content was investigated under complicated conditions where the frother dosage, gas velocity, and froth height were changed together. For the froth properties under study, their degree of correlation with clean coal ash content decreased in the order of homogeneity, water recovery, gray value, and froth velocity. The coefficient of determination (R-2) of the fitting relationship between homogeneity and clean coal ash content was as high as 0.9028, because homogeneity has a close correlation with the foam structure and foam destabilization behaviors.