Abstract: Taking the SSAW pipe in K60 steel as produced for Russian Tajset-Perevoznaya Bay Oil Pipeline Project as the testing pipe,the change of the residual stress of the SSAW pipe before and after expanding is measured by means of cutting the pipe into test pieces,and distribution characteristics of the pipe’s residual stress as well as the improvement of the residual stress as resulting from the expanding process are analyzed.The said measurement and analysis results show that there exists considerable residual stress of the pipe before expanding,and the expanding process contributes to significantly reducing the said residual stress.