The stress corrosion cracking of Austenitic stainless steel was studied using thepolarization technique, slow strain rate and Scanning Electoral Microscopy (SEM) techniques. Anumber of SCC mechasms have been proposed, in which the hydrogen embrittlement theory andpesive film rupassivation theory are generally accepted. However, they cannot sufficientiyexplain the SCC mecbanism of Austenitic strinless steel in acidic chloride solution, because the steelis in an achve dissolution state in the solution, and cathodic polarization can prevent the SCC fromoccurring. It was found that the SCC of Austenitic Staiuless Steel occurred, although the steel wasin the anodic dissolution state and the morphology of the fractured surface was characterized bybrittle cleavage. ms kind of SCC cannot be reasonably explained by the passive filmrupture－repassivation theory and the hybogen embrittiement theory. ln mis paper, a fracturePrDbality compehhon mecbosm of SCC was presented, on the basis of: the experimental resultsof the relationships between anodic dissoluhon and deformation; staln distribution measuremcnt bySpeckle Interferometry; and fracbed surface observation combined with the viewpoint of ductile－brittlefracture competition. This kind of SCC mecbosms not only explain the propagation of SCC cmeks,bu also the crack initiation.