Carbon fiber reinforced aluminum matrix composites with uniform fiber distribution were prepared by ultrasonic vibration method.The effects of vibration time and parameters on mechanical properties of the composites prepared were investigated by scanning electron microscope（SEM）and electronic universal testing machine.The results show that ultrasonic vibration is obviously helpful for the filling of carbon fibers with molten aluminum completely.And the tensile properties are increased with the increase of vibration time.With the vibration time increasing from 10 sto 30s

the tensile strength of carbon fiber reinforced aluminum matrix composites is increased from 105 MPa to 130 MPa.