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It is difficult to evaluate the corrosion crack growth resistanceparameters due to specific morphology of cracks (curvilinear propagation path,branching, corrosion and deformation blunting). In particular, the high-strength steelsexhibit a curvilinear path of the cracks propagation and their intergranular branching,caused by the grain-boundary subcritical crack growth. For ductile materials the effectof deformation crack blunting due to active loading of a specimen and its sustainedloading as well as corrosion blunting because of interaction of the specimen freesurfaces with environment are very important. The experimental procedure forevaluation of peculiarities of the corrosion cracks growth is proposed. To take intoaccount the corrosion crack branching, KIeff was evaluated, which was assumed toequal the maximum KI value achieved at the tip of one of the crack branches. It hasbeen shown that the account of the morphological specific features of the corrosioncrack growth are very important for the correct evaluation of service characteristics ofmaterials and determination of the environment influence mechanism. It has beenshown that the precision of evaluating the KIscc level decreases and the usage of outerpolarization for evaluation of mechanism of corrosion environment effect can lead tothe wrong conclusion if the possible variation of the crack morphology is not taken intoaccount. These peculiarities are very important for the correct evaluation of servicecharacteristics of materials and for an examination of the rupture causes of thestructure.