Ultrasonic vibration friction and wear experiments were carried out by MFT-R4000 reciprocating friction and wear tester bonded with ultrasonic device. The surface morphologies of wear scars were examined by scanning electron microscope (SEM). The influences of ultrasonic vibration on friction reduction and anti-wear properties of GCr15/45# steel frictional pairs under different loads were discussed. The experimental results showed that, the friction of GCr15/45# steel frictional pairs could be reduced by ultrasonic vibration, and the reduction of friction coefficient became more obvious as the loads increasing. The friction coefficient measured under ultrasonic vibration is 12% lower than it measured without ultrasonic vibration when the load was 50N. However, the wear of frictional pairs increased under ultrasonic vibration, and the amplitude of wear volume enlarged with the loads increase, which is 63% at the load of 50N.