An ultrasonic transducer, an ultrasonic probe, and an image diagnosis apparatus perform an ultrasonic procedure. The ultrasonic transducer includes: a piezoelectric layer an acoustic matching layer disposed on an upper surface of the piezoelectric layer and a plurality of back efficiency layers that are disposed on a lower surface of the piezoelectric layer and have different acoustic impedances. The sensitivity, bandwidth, and pulse length of the ultrasonic transducer may be controlled by appropriately changing acoustic impedances and thicknesses of the back efficiency layers.
