Electrochemical noise technique coupled with SEM was used to study the corrosion process of LY12-T3 in the modulated EXCO test solution, and the EN data were analyzed by wavelet technique based on orthogonal db4 wavelet. The results show that, under the experimental conditions, the characteristics of energy distribution plot (EDP) obtained from wavelet analysis technique can be used as "fingerprints" of EN signal and can be used to differentiate the corrosion type. With the change of corrosion type of LY12-T3 from pitting corrosion through intergranular corrosion to exfoliation corrosion, the maximum relative energy defined in EDP will change from the region of crystal series coefficients with smaller scales through middle scales to larger scales. (C) 2005 Elsevier Ltd. All rights reserved.