In an initiation stage of stress corrosion cracking, a number of very local anodic events and their repassivation occur in stochastic manner. The target of this study is to develop an experimental method, which enables us to observe the local and transient anodic events taking place in a wide area in the SCC initiation stages and resultant formation of SCC embryo with a resolution of a few micro-meters. Visualization method for SCC initiation processes has been successfully developed by using coloration reaction between Fe and phenanthroline. Performance of the method has been demonstrated for SCC of sensitized 304 stainless steels. The sensitivity was as good as to visualize formation of 3 micro-meter pit. For a sensitized stainless steel - a sodium thiosulfate system.