The stress corrosion crack propagation of cold worked AISI 304 stainless steel in boiling MgCl₂solution was investigated. The crack propagation rate is not affected by the amount of cold work except the one cold worked 60%. It was found that the resistance to stress corrosion increases as the amount of stress induced martensite increases to certain amount, but beyond the amount the stress corrosion crack accelerates to shorter life. The higher degree of cold work shows the higher K_(1scc).