Abstract: To reveal the characteristics of acoustic emission(AE) for ductile materialsduring damage accumulation,a series of tests were carried out in our laboratory. Thispaper presents several AE results about static and fatigue loading induced damage behaviorfor A3 structural steel.Different AE properties are discovered when A3 steel underwenttension,fatigue and then tension。 Two peaks in the AE counts vs.time imply differentdamage states for the specimen during static loading after fatigue,yielding and damageaccum...