The effects of ultrasonic pretreatment on the flotation performance of coking middlings were investigated through a flotation cell. The surface properties of coking middlings before and after ultrasonic pretreatment were indicated using X-ray fluorescence analyzer (XRF), scanning electron microscope (SEM) and DSA100 contact angle analyzer. The flotation results demonstrated that the combustible recovery increased by 7.18%, while the ash value of flotation tailings decreased by 2.74% at most after ultrasonic pretreatment. Flotation results were supported by XRF analysis, SEM analysis, and contact angle measurements results. These results show that the ultrasonic pretreatment has a beneficial influence on the flotation of coking middlings.