Stess corrosion behavior and cracking mechanism of 2205 duplex stainless steel (DSS) in saturated H₂S environment were studied by using C-rings Stress Corrosion Cracking Test. The results showed that 2205 DSS has good resistance to stress corrosion in Test Solution A of NACE Standard. Through OM, SEM, EDS and electrochemical analysis, stress corrosion cracking in 2205 DSS undergoes the following procedures: pitting corrosion on surface, formation of corrosion hole, dissociation of H₂S, absorption of H atoms and their diffusion from corrosion hole to inner metal, then gathering at some place in matix, finally initiation of cracks by hydrogen induced cracking mechanism and their gradual propagation.