Traveling wave ultrasonic motor (TWUSM) is driven by friction force between stator and rotor. As the friction materials of contact layer in traveling wave ultrasonic motor(TWUSM), tribological properties of Ekonol composites(EK2) have important effects on motor driving characteristics and service life. Then EK2 was stuck on the stator tooth of 40 type disc-shape TWUSM. Under different driven mode and friction combination, tribological properties of EK2 was tested，and the wear morphologies of EK2 surfaces are observed by SEM. Results show that there are ultrasonic antifriction phenomenon in stator/rotor contact interface under ultrasonic drive. Ultrasonic fatigue is the main wear mechanism of contact layer. When Ek2 combine with Cu rotor， contact layer can obtain bigger friction coefficient, higher output torque and better wear properties. Then Ek2 and Cu rotor is a good friction combination which can satisfy the actual running needs of TWUSM.