Flotation performance is expected to be affected by froth characteristics due to the changes in the operating conditions. However, very little study has been undertaken to investigate how froth behavior responds to the flotation variables. This study presents an experimental program performed to investigate the effects of flotation variables including gas flow rate, froth depth, slurry solids percent, frother/collector dosage, and pH on the froth features such as bubble size, froth velocity, froth color and froth stability during desulfurization of an iron ore. These parameters were varied using a central composite design (CCD). Image analysis methods have been developed and employed successfully to characterize the froth features. Results of the CCD experiments showed that the flotation variables have different effects on the froth features. The effect of pH and its interaction with collector dosage have a significant impact on all froth features. Process condition can be accurately deduced from the froth surface appearance which provides a convenient way to quantify the parameters as the process control function.