Abstract: It was illustrated that the crack in hot-rolling plate and strip often can be found in production examination and application. The cracks of plate and strip was analyzed by means of chemical analysis,macroscopic and metallographic examination. The results showed that composition was normal,the main reason of the cracks of plate and strip were sub-surface porosity,nonmetallic inclusion and free cementites. In order to improve the quality and meet the users requirments the advice had been proposed.