Abstract: In order to investigate the effect of ultrasonic simultaneous treatment on flotation of fine coal slimes,a new ultrasonic flotation device was made to conduct floatation experiment. The particle size distribution of clean coal particles was investigated by SEM.The influence of ultrasound on adsorption of collector was investigated by UV spectrophotometer.The result revealed that combustible recovery and perfect index flotation of floated products increased by using ultrasonic treatment with same reagent dosages.The best flotation effect can be achieved with 100 kH ultrasound , and the combustible recovery rate is 10% higher than that of conventional flotation.Ultrasonic floatation need 19%~35% less reagent dosages than conventional floatation under the same flotation condition.Ultrasonic can remove the fine mud adsorbed on the surface of coal particles , promote bubble agglomeration in the pulp,form air flocculation ,and improve the flotation efficiency of particles with size of +0.045 mm.