Abstract: The cracking reasons of a rolled high strength steel plate in the process of tube-making were analyzed by means of macro analysis, chemical composition analysis, metallographic examination, fracture analysis and tensile test at ambient temperature. The results show that many non-metallic inclusions and stress concentration caused by central segregation were main reasons for the cracking of the high strength steel plate in the process of tube-making. In addition, the uneven mechanical properties along the width direction of the steel plate also promoted the cracking. Finally, the preventive measures were put forward according to the cracking reasons of the high strength steel plate.