Abstract: Basic principles and characteristics of ultrasound excited thermography testing were introduced. The excited ultrasound could produce mechanical vibration at the defect. Because of the thermo-elastic effect and hysteresis effect, the defect location would release heat. At last, the heat releasing process was monitored by the infrared thermography and the infrared image was analyzed with a special software. Because of the modulating function of excited signal frequency and special image process, ultrasound excited thermography had some unique advantages. Testing on the aero material such as carbon fiber reinforced composite showed that this method could detect the defects such as crack, delamination and break effectively, and had a widely application prospect.