In this study, a newly developed ultrasonic wave-visualization technique was applied to scarf-repaired CFRP laminate with the artificial defect and an actual scarf-repaired part. The technique enables to visualize ultrasonic wave propagation and to detect damages by using the wave-visualization technique. First, impact damages in the CFRP joint specimens simulating scarf repair was observed by ultrasonic inspection and cross-sectional microscopy after impact test. Secondly, CFRP scarf-joint specimen with the artificial defect was inspected by using the wave-visualization technique. As a result, scattering and velocity change of visualized ultrasonic wave were observed at the damage area in scarf-repaired composite. Finally, an impacted scarf-repaired specimen was inspected by using the wave-visualization technique. The damage area was detected by visualized ultrasonic wave propagation. These results demonstrate that the wave-visualization technique is quite useful in damage detection of scarf-repaired composites.