Abstract: The reconstruction of crack profiles is getting more and more important in the NDE of structures such as pressure vessel, tubes in heat exchanges. Based on the different generation mechanisms, the cracks were classified and the differences between artificial and natural cracks were analyzed. The crack profiles were reconstructed based on artificial neural network and the reconstructed results validated the method being having many advantages, such as high speed and precision. The drawback of this method was also discussed and the measures to overcome it were proposed.