Abstract: Types,causes and influencing factors of linear defects on cold-rolled sheet were analyzed by such detection means as field emission scanning electron microscopy,energy dispersive spectroscopy and optical microscopy.The results show that typical linear defects on the sheets include bubble,scratch,inclusion and press-in of iron oxide scale,and most of the inclusions are entrapped from casting powder.In order to eliminate those typical linear defects,countermeasures for the processes like converter steelmaking,tundish metallurgy,and high pressure water descaling are proposed.