Abstract: A 3D ultrasonic imaging technique by using B-scan and T-scan imaging methods, based on sonic information resulting from reflections of probe beam at interlaminar interface, was employed to non-destructive evaluation (NDE) of interlaminar defects in carbon fiber-reinforced/resin matrix laminates. The experimental results had shown that the interlaminar interface, interlaminar defects, their topologies as well as lay-up of the laminate were seen well by means of the ultrasonic imaging approach. It provided an effective instrument for NDE of interlaminar defects and characterization of bulk microstructure in composites.