Abstract: Strain aging effect is likely to bring about increase of yield strength and yield-to-tensile ratio of linepipe steel as well as significant yield point elongation on stress-strain curve.The manufacture and application of line pipe and steel were investigated and it is pointed out that strain aging is harmful in most cases such as the quality control during pipe manufacture,butt welding and pipeline service.Measures such as lowering temperature of specimens,preparation,controlling heating temperature and time of coating,lowering C and N content in linepipe steel and developing two-phase steels as well as performing on-line heat treatment just after accelerating cooling are helpful to minimize strain aging effect.Finally,the characterization parameters of strain aging effect for linepipe steel were suggested.